The answer is absoluely YES. The 360 will get significantly more titles than the PS3. But in a somewhat disappointing way.
Almost all the 4rd party AAA titles will ship on both platforms. No third party should ignore 40% of the HD market after putting in 10s of millions of dollars in investment into the game and buying into the Unreal Engine multi-plat dev platform.
But three classes of titles will be skipping the PS3 regularly:
1. The PC based titles:
Titles that have their roots in the PC architecture will migrate readily to the 360 architecture but will find it very hard to adapt to the PS3 format. The PS3 is just too different. With reasonable success of some RTS games on the 360 I think we'll start seeing more and more PC titles released in PC-360 formats but skipping the PS3.
2. B titles
Titles with limited budget guidelines and quick release schedule will go with a single platform and the 360 will win by deafult here. These titles will not be willing to pay Epic royalites and will happily work directly with XNA or DirectX of the 360. The developement is quicker, there is only one platform to test with and the product is optimized for the full capacity of the console. If they have done a good job or have a new creative idea , they may get Microsoft to pay for some of that (See Lips or You'r in the Movies).
You may think you don't care too much about B titles but there is a real market for them. People are buying them and paying good money. None of them is a million seller but in an aggregate they make up a very significant volume.
3. Community games
I don't think people here realize yet the potential impact of XNA on the gaming market. Expect to see hundreds of games per year released through the XNA channel. In 2009 more community games will be released on Xbox live than full budget titles released in retail. Like B titles, most will sell very modestly. But some will become major hits. See Braid for example.
All together, I expect that in 2009 the sheer volume of titles released for the 360 and not showing up on the PS3 will be migher than the titles showing up on the PS3 (exluding PS1/PS2 and XBOX releases). And I am willing to take bets on it.
Prediction made on 11/1/2008:
Q4 2008: 27M xbox LTD, 20M PS3 LTD . 2009 sales: 11M xbox, 9M PS3







