But if they say "we can't answer that at the moment", it probably means "if we told you the exact reason, we'd p*ss off one or other of the suppliers and then the deal the lawyers have spent months working towards will go south rather quickly." Negotiations
can often be very sensitive and talking about them openly doesn't necessarily help the process.
Then they can say "we are unable to discuss details with you right now, but we are in negotiations with various people hoping for a resolution in time for Windows Phone 7's launch in Europe"
It says nothing specific, gives us hope for launch, and explains what's happening.