Another vote for Wombat in the debate that Microsoft should not have forked over more money for exclusive titles. My friends that have XBOX's are asking for 360's this year and getting the 360 bundled with Gears Of War as that's one game has been identified as the "killer app" in our group.
Why should MS spend money on exclusive titles when Sony doesn't even have enough units in the hands of gamers to justify an exclusive title? Most of the units right now are pending in EBay auctions. Even if the title is out there for both systems at this point the game most likely looks better on the 360 and offers a better online experience. (Did someone say "no in-game friends list for Resistance"?)
From what I can see, the online experience for PS3 owners is a joke and that's the reason why they're not charging for an online service like XBOX Live. Sony is relying on their brand recognition for the PS3 along with the perception that the PS3 is much more powerful than the 360 for the graphic whore gamers out there.
It should also be noted that MS has made some strides in removing exclusive titles from Sony such as GTA and Assassin's Creed (that was most likely never an exclusive to begin with). The Metal Gear Solid series could be next and the rumors are flying. Preventing Sony exclusives is just as effective as securing 360 exclusives for your system as you keep the choice of consoles in the hands of the gamer.
The XBOX Live service and the ease of development on the 360 are going to become bigger issues in the coming months as the consoles continue to square off against one another. I'm a HUGE Insomniac fan (Ratchet & Clank rocks) and if Sony can't get those guys the information they need to integrate their game with an online service something has to be wrong. My opinion is that Sony will suffer in the long run by shifting the work of online tools directly to the game developers making it increasingly difficult for gamers to connect online. If I wanted to play an online game and had to configure multiple tools to do so I'd play on a PC and not a console.