Think for a moment. Besides the technology, what's really so different about today that makes it distinguishable from the '90s?
Here's the biggest changes I can think of: video games are much more complex, movie special effects have made leaps and bounds, portable computers are the norm, and the internet has changed the way we communicate and access information.
Aside from that, the biggest cultural change, I think, is our almost total abandonment of old-school cartooning, in favor of CG animation. Would you see a show like Animaniacs made today? Probably not. That sort of thing is slowly coming back again, but not so strongly as it did after Who Framed Roger Rabbit?.
The world of entertainment tachnology is going strong, and progressing like a bullet train, and I'm totally in favor of it. But have you ever noticed how teenagers are still dressing like the latest blond diva or gangster rapper? Take a look at the comic strip Curtis- that kid has been dressing like a rapper since 1988, and his clothes are still in fashion. Perhaps clothes have become less colorful since the '90s, but I swear, I'm in my early twenties and I can't distinguish a kid from today from a kid I saw when I was eleven.
The 20th century tends to be subdivided into individual decades, and for good reason- they're clearly distinguishable from one another in regards to fashion, music, cinema, and the arts. You can always see a relationship between one decade and the next, and when you've done as much internet research as I have, they all start blurring together, but they're still distinguishable.
I didn't really find 2000-2009 terribly different from my childhood years of 1995-1999, culturally.
We're in an age called the Age of Information. I can tell you from personal experience that it is vastly easier to find resources online than it was when I first started using a computer. What this means is that you can find almost all human knowledge by going on the internet, so anybody with internet access can learn about any subject they please. Before, you had to go to a library and hope you get lucky.
In particular, an artist of any sort can go on a path of discovery and acquire interests that may been impossible before. Think about this for a moment: your favorite guitarist, if he or she started their careers before the internet was invented, was only able to absorb the music that was available to them. Generally this meant what was sold at record stores, or played at concerts. Usually it's only a particularly sharp musician who bothers to dig a little deeper and scour the used records bin, go to libraries, or travel to distant places to discover music that wasn't newly on the charts.
A huge part of the success of '60s/'70s giants like The Beatles, The Who, Eric Clapton, and Led Zeppelin is that they didn't merely copy the most popular and current hits- they went a step further. That takes a bit of work.
But now it's easy to do that, and it only takes curiosity to propel a person forward into unexplored territory.
So a musician can listen to any sort of music in the world.
A painter can look at any visual medium they like.
And even a chef can find places to purchase exotic ingredients and learn new recipes.
I don't think that this is so bad in of itself- not at all, in fact- but what it means is that it's nigh impossible for any artistic decisions to be spontaneous. Elvis Presley had no clue that what he was doing was something new- it was just music he grew up with and imitated as far as he knew. Limited availability of information meant that a new form of art could pop up out of a stew that was thrown together accidentally- many of the most important cultural changes were merely the same recipes created a few years ago, but with a new ingredient added or subtracted. This spontaneous addition and subtraction is what kept these things surprises.
With easier access to information, the changes become more and more conscious. Your basic folktale wasn't changed because the teller knew about some specific version from a century ago- it was changed because the teller had a whim or didn't remember the previous version quite the same way. Pop culture used to be a game of telephone.
A writer can look at a book about fairies- dozens of books about fairies, in fact- and decide that they want to turn something around and make it a different color. An accidental change is rare these days.
(I'm not including such cultural changes like modern and/or abstract art, since those were conscious to begin with and not popular culture.)
When it comes to music, I think I can pinpoint the beginnings of conscious cultural changes to about the late '70s, when music critics began labeling the many branches that were rapidly forming out of the major rock 'n' roll subgenres. When you start subcategorizing styles, its inevitable that people will start becoming aware of the differences, whereas people in the '50s didn't really think about what distinguished one style from another, and most labels are retroactive. I personally blame the various revivals of '50s and '60s music and punk and metal, because they're the main "offenders" of subcategorizing, even if the musicians themselves aren't the cause of it.
When you start looking at a chart, point your finger at something, and decide "I'm going to play THIS kind of music", you're not being spontaneous anymore. I admit that even I do this.
Since the '80s, pretty much every musical movement has been some sort of revival, deliberate distortion, or hybridization of some previous style. To me, the last truly original musical style was grunge and alternative. Think about it: Madonna shocked the nation with her outrageous costumes and sensual performances, set to synthesizers and drum machines. Britney Spears did the same thing. Now it's Lady Gaga.
Right now I'm looking at the soundtrack CD to the Super Mario Bros. movie. It was released in 1993, and except for "Tie Your Mother Down" by Queen, none of them date earlier than the year before. Besides the metal of Megadeth and Joe Satriani, and of course Queen, none of the tracks sound much different from what you'd hear today. Guitar-based music has drifted in and out of popularity, but you still hear rap, electronic pop and alternative/pop-punk/post-grunge, despite this stuff being around for at least 20 years! Compared to previous decades, twenty years is a long time for a form of popular music to remain mainstream.
I can't think of any work of art that's been made the past decade that isn't some sort of deliberate revival, imitation, extension, reinterpretation, subversion or aversion of some previous work. The key word here is "deliberate". Now, mind you, there are some styles that I think ought to be kept alive, and aren't played with nearly enough, but I haven't witnessed a cultural revolution or innovation of any sort. My generation seems to have missed the boat when it comes to revolution, because there's not really anything to rebel against, besides corrupt politicians (but that's nothing new, either).
Now, I'm not saying that it's going to stay this way and we'll have nothing new forever and ever. It CAN'T stay this way. But it's going to take something totally out of left-field, some mixture or reinterpretation that the people at large didn't expect, to shake things up and give pop culture a new face. That's the way cultural changes have been done before (ironically).