I don't know why people are waiting for PS3...
Sure... it will be probably be great, but not too much is known about price, what games will be available at launch, what will be included in the box....
I can tell you 1 thing... about it... it has the ugliest freakin controller since the Atari Jaguar.
With XBox 360, we all know what you get:
Premium $399:
XBox 360 system with chrome DVD tray
1 WIRELESS controller
XBox Live Silver membership
XBox Live Gold 30 day trial membership
Headset/Mic for online chat / voice recognition in games
20 GB Hard Drive
Standard TV and HDTV connectors included
LIMITED TIME- Bonus media/DVD remote included (Green sticker on box indicates whether you get it or not)
Plays mulitpayer games online via XBox Live Gold*
Plays many original Xbox games with more games added every month!*
*These features require the 20 GB hard drive that is included in the Premium pack.
Core $299:
XBox 360 system (without chrome tray)
1 WIRED USB controller
XBox Live Silver membership
Standard TV connector
While it is obvious which configuration is the the better deal, at least Microsoft is giving people a choice. Some people are simple, just want to play games and don't care about the rest of the stuff. They may be on a budget... the $299 system is perfect for them.
The $399 is the best bang for your buck.... especially if you are gonna play online, and have or will be buying an HDTV.
Right now with PS3... we don't know the price and what you will get at that price! Also... if you are "waiting for PS3" because you just cannot find an XBox 360... next year, it will be the same or worse when you try to find a PS3. PS3 launch will be more popular just due to the fact the Playstation has the most brand awareness than any other video game system. People will check it out due to word of mouth. "Hey man, the new Playstation is out."
Also... once again... would you rather play a game with this controller:

or this one: