Uncertainty.
The length of time until the reveal is irrelevant. There shouldn't and isn't any justifiable reason we're being kept in the dark unless Intel themselves haven't told their partners (which they have because Gibbo has stated OCUK will have competitive pricing and he couldn't say that if he didn't know what they are).
+1
It is strange that no e-tailer has listed the IB chips even though the product has been officially launched and the release date to retail is so close. You'd of thought that they'd want to get as many pre-orders in as possible to cope with any surge they may have.