I own neither a PS3 or an XBox 360 - so I have zero skin in this game either way.
But I *have* been watching the development of these two series for years now and have been paying especially close attn to the latest iteration of both.
And from my outsider's perspective, it really looks like 360 is pulling hard away from PS3. I don't just mean the Forza and GT series, I mean the peripherals (kinnect) and their impact on these titles and so therefore others.
PS3 imo has alot of playing catch up to do.
If I were to buy a console tomorrow, it'd have to be the 360.