Sony's Walkman NWZ-X1000 features an OLED touchscreen, Wi-Fi and built-in noise cancellation. The X-series Walkman seems like a very impressive piece of hardware.
Much like its direct competitor, the iPod Touch, it comes in 16GB and 32GB flavors and can be used to surf the web. The screen's half an inch smaller, but it's also OLED (rather than the Touch's LED) so you can expect brighter colors and better contrast.
It also comes with digital noise canceling-a first for any MP3 player I've seen. The feature, allows any accompanying 13.5mm EX headphone to block out ambient noise, and basically renders those expensive Bose earphones you just got for Christmas obsolete.
What I like about this is that it's one of those "D'oh, of course!" ideas. I've always hated how the sound gets muffled and crappy (or turns off completely) when your noise canceling headphones run out of batteries-you don't have to worry about that if it's all incorporated into the MP3 player.
We'll have to run it through the standard tests to see if it's all it's cracked up to be, but what worries me most about the X-series, and it's most likely roadblock to widespread success, is the price. Right now it's TBD. Sony has come out with a ton of outstanding MP3 players, but unless it's willing to sell this one for $400 and lower, the X-series probably won't knock the iPod Touch off its perch.