sorry
you can use multiplatform games if they've had the same amount of time with final dev kits and are based on technology that's had as long to mature. that might actually be the case for Half Life 2, but i doubt it.
i'm actually eager to see if the same kind of ATI/NVIDIA differences we've been seeing carry into the new consoles. will the hl2 engine run better on the ATI (AMD Radeon?) powered system and will doom 3 powered games run better on the NVIDIA powered one?
what you really need, is two equally talented devs to spend equal time making exclusives for both systems with comparable assets.
what i heard from people at lucasarts at E3 was that it was easier to tap the 360's power but that the ps3 had more power. that makes me think the multiplatform titles aren't going to the ones that really show the difference between the two in terms of raw power and that the 360 might actually come off looking better on multiplatform titles over all, with the ps3 having a few exclusives that the 360 couldn't pull off.
now whether the perceived performance crown will go to the one with the more powerful hardware or the one with the better looking multiplatform titles, is something i'm really looking forwards to finding out.
but hey, F.E.A.R. is a good game in any console's library and if they are sweetening it with exclusive content (presuming it's getting the same bonus content that the 360 version has) the PS3 version may yet be the one to get.