According to this article
, Famitsu (one of the bigger Japanese gaming magazines), is reporting that the Xbox 360 will ship with 20 launch titles. This number seems a bit high to me which means that they know about a few titles I don't know about (probable) or they are including some of the titles in the launch windows (the period between when the system ships in November until the end of the year).
Another interesting tidbit in the article is that they mention a "secret feature" that will be built into the 360 that won't be activated until a year after the system launches. If you put this into the context of the three versions of the Xbox 360 rumor it might mean that Microsoft may be launching some kind of DVR software upgrade at that point (perhaps in coordination with the announcement of a bigger hard drive).