I do't know...theres alot to factor in.
2010 line up of 360 games is impressive..Sadliy Sony just doesnt look as hot besides 2-3 titles..that may or may not come out*im looking at you GTforever*
Natal...theres no telling what it can/will do...theres a chance it could hit like the wii...but then again..so can sony's.
Price cuts...if acrade hits 149$ and elite hits 249$...idk..but many who have been holding off this gen or already wii owners have a good chance at getting on the hd360 boat.
I'd see sony hittin the market with a KO punch....if it out just about all ps2/1 titles upscalled on psn.