I will make the plunge quite late in the cycle as the 360 / Wii fulfill all my gaming needs at the moment.
The PS3 is just too expensive with little or no games to recommend it over the 360.
Problem is I cant see the games coming. Its not just an anti Sony thing (I am a confirmed Sony hater by the way) its simply looking on the Horizon the big hitters dont do it for me.
MGS4 - have never liked the series one iota
GTAIV - Is coming out for the 360
Final Fantasy - see MGS4
Microsoft seem to have cornered the games people want to play this gen.
Basically until God Of War pops his head out of hades I'm more than happy to let the PS3 chase down the other two consoles and will buy in 4 years or so at a vastly reduced price.