It seems that this year's E3 is a little bare when it comes to first party games coming out of Microsoft's studios. This could either mean that it's a slow development period for the developers, or the more likely answer, that they're holding out for another week. Rare seems to be one of the developers doing exactly that.
Just after re-branding their company, it seems rare is also teasing a new game announcement at E3 this coming week. According to the Rare site at the time of writing, the announcement is seven days away, which means that this surprise should be coming along on the first day of E3.
If Rare has a new game out, it's pretty exciting news. Sure their first few games on the Xbox 360 were a little off, but they seem to be hitting a stride with their more recent titles. Even if they have some sort of new twist on Banjo-Kazooie, I'll be happy.