the PS3 has better HW (no rrod, bluray, more powerful, free online)
the 360 has better online (or so i here) and a better selection of games (as of right now)
I personally chose a PS3 over a 360 because the HW is better, and GT5 is looking really awsome. Most of the games I wanted besides GT are on both consoles (CoD, Oblivion, Madden)
basically, you like me being a Wii owner might be a better fit for the PS3. The Wii and PS3 have no overlap, the 360 overlap a tap more (but not much still)
So my advice, which is the though process if you are into Halo, Gears, or Fable- I would get a 360.
If you think you are more into MGS, GT, Uncharted, killzone, or Resistence, and dont yet have a BD player, then get a PS3.
End of 2009 Predictions (Set, January 1st 2009)
Wii- 72 million 3rd Year Peak, better slate of releases
360- 37 million Should trend down slightly after 3rd year peak
PS3- 29 million Sales should pick up next year, 3rd year peak and price cut
