The 360 will display a 720p/1080i output, however when tested with a Hi-Def screen, versus a standard 37" Panasonic Viera (which I have
How? Why?
Well in lamens terms, all though the Hi-Def plasma (can't remember the make now) showed stuff very vividly, and shiney, the overall effect was worse, as it had to downsize to 480p, as hardly any Plasma screens here in Europe can support that resolution.
When downsized on the hi-def screen, it made all the edges of everything on the screen really blurred/bitty, and did not show off the console as the "promo stand" had intended.
The Panasonic Viera, which runs at 480p anyway, has a very good downscaler, and when viewed, actually looks a lot less broken up around the edges, giving an overall better look to the screen.
So basically to sum up, Hi-Def is a big load of bollocks (as I had already thought) as nobody can agree on a standard, and because we are so behind over here in Europe, if they don't downscale the output of the consoles before release (which must be too late now), the quality of the images on screen on current Hi-Def plasmas are going to look shit in comparison.
If you are thinking of buying a Plasma screen, save your money as there are a lot of cheap/good non-Hi-Def one's around now (particularly Panasonic Viera one's), and you won't really be using anything that deals with Hi-Def properly for another 2-3 years at least, by which time you'd probably be buying another one.
/breathes



