You would be suprised at how many team who are sponsored by a bike company on't actually use their brand.
Giant is a company who sell a lot more bikes in the low-end market - Tell me why people like Jan Ullrich, Alexandre Vinokourov, Erik Zabel would drop from high-end Bianchi's and Pinarello's to the low-end Giant?
One of the main reasons for using another company's bike, but puting different decals on it, is Marketing. In order to market the brand, they will sponsor the best of riders, but the best of riders need quality bikes, and if they don't make quality bikes, they turn to other companies.
So what would people expect T-Mobile do with the Giant Sponsorship? Put stickers on their "Giant TCR"
Dude, you need to just shut up about this thing. Riders that do have different frames then the brand there sponsered with are usually like a time trial frame, or just with one rider or two riders do it, not a whole team. In the case with T Mobile everyone will be riding TCR composites.
Once rode them, Beloki rode one. IMAGINE THAT! They must definatly be crap then!
This isn't a case where a team is riding Litespeeds with different logos. You don't know what your talking about.
Making crap up isn't a good way to start out.