Great first post bud. I think the true war of the 360 vs. PS3 (leaving Wii out) is what platform is the LEAD system these multi-platform games are developed for.
Great example: FNR3. It's selling almost as well as the PS3 version, despite the fact that it's a year old on the 360.
The true merit of how "good" the graphics on the PS3 are is not tied up in how fast the SPEs are, but how efficently and quickly developers can and will utilize them. The reason the PS3 is far from any sort of major contender for this generation (in terms of matching the 360/Wiis # of units sold a year) is because it's taken a major flaw of the PS2 and magnified it: Developer difficulty in utilizing the power of the system.
Sega lost MAAAJOR ground to Sony and Nintendo not because the Saturn was a bad system, but because it's dual-core nature prevented most every developer from using both cores to produce a brilliant game. The Saturn was a better CD-driven system graphically than the PS1, but it lost because the games developers made for the system weren't very good due to the nature of the system, and too much extra cost associated with making the games better.
The breaking point is if Sony can somehow develop middleware, developer kits, or something to allow the big ones like S-E, EA, Konami, Namco-Bandai, Activision, ect to make the PS3 a lead console for development on the multi-platform games. They can do this by making the PS3 graphics/gameplay better than the 360 for the same # of development dollars. However, at this point that can't really happen. The SPEs are more difficult to get the same amount of power out of vs. 360, and thats why it's not only lost alot of games, but the 360 is the lead console: It's Saturn vs. PS1 all over again. Sony can easily turn the corner, however. 3-4 years from now the PS3 could easily become the lead system IF Sony was able to convince developers that the PS3 is the best choice due to the fact the SPEs ARE better than the 360. There's no doubt to it.
However, the 2x power of the SPEs mean nothing if developers have to pay more to use the power on a system of a smaller fanbase than the Wii/360. That my friends is the dealmaker and dealbreaker. Why should a dev make the PS3 a lead system for a multi-port game when it'd cost more and return less? It's simple economics.
The Wii has the advantage of multi-plat games being semi-cheap (however, they'd still have to dumb down textures and invent wacky Wii controls for the system).
The 360 has the advantage of getting close to the PS3's graphical prowess without the associated costs of it. Yes, it's considerably more costly than the Wii being a lead-platform game, but it returns the cash by the large user fanbase (still #1 worldwide and still the lead platform of 3rd party & multi-plat games).
So those economic factors will inhibit us from seeing alot of MAJOR 3rd party games making the PS3 a lead platform for the near to mid future. Sony, however, will produce brilliant PS3 games showing how good the system can look.
Hopefully, S-E jumps ship and I can get myself FFXII and FFXIII on my 360 (KH3 would be good too). My girlfriend at that point won't be mad that I'm a 360 owner and not a Playstation owner :)
Back from the dead, I'm afraid.
Essay Pro