Ok First off:
Storage. HD-DVDs in Xbox 360s
According to the link (it's one of many that has the same information), the Xbox 360 could arrive with HD-DVD from Toshiba as it's optical drive, or later releases off the 360 will contain the HD-DVDs. These are comparable to the Blu-Rays that Sony are using.
(And if people get worried about buying a DVD unit and then the HD-DVDs come out, look at the Xbox. The first price drop, everyone who bought an Xbox at the start and registered, got a choice of free games to make up for "not waiting". Not to mention that when any of the Thompson drives went kaput, they replaced them ASAP (mine was next day replacement) without a single gripe.)
Power.
Game developers have stated that they cannot use the multi-core systems to their fullest. They have not got the software or knowhow to put to use all of the cores in the PS3, and to a lesser effect, the multi power PC processors in the Xbox 360. However, the Xbox 360 will make up for it, by using the processors the same way a dual core processor works now, by putting the game on one of the processors, while things like live aware, or music playing will run on the other(s). Game devs have also said it could be anything up to TEN years before they can fully unlock the capability of the multi-core systems.
While this is worrying at start, it also makes for a very interesting future. We will see games on both consoles that surpass the previous gen, but then three or so years down the line, when we'd see a new console generation appear, if they unlock the ability to use the multi-cores to their fullest, it will be like a new generation... without having to spend £300 on a new console.
I'm going with the Xbox 360. I'll get a PS3 and Revolution after the price drops, but Xbox have not let me down so far. I'm not a "fanboi" or whatever people call "loyalists" these days, but i play on the Xbox much more than the PS2, even though i have more games for the latter. Its just after a while, the PS2 games feel... samey, especially having been a heavy PS1 collector too, and there never seems to be anything "new" to arrive (not in the UK anyway...) that changes the view. Also, the stuff Sony have come out with in this "console war" has been so idiotic, it makes me wonder if it's worth giving money to a company that employs idiots to handle PR.
"The PS2 is more powerful hardware wise than the Xbox" (this was a year or so after both are released).
"The PS2 will allow users to enter a Matrix like world" (you mean Enter the Matrix? Guh that was awful.), and then some of the latest comments...
"The Xbox 360 is more like a Xbox 1.5" (combined processor power of 3.3ghz, compared to 700mhz in the Xbox, doesn't scale to 1.5x more powerful...) and then
"The PS3 might be more expensive, but people should work more hours to buy one". (George Orwell, eat your heart out.)