I can think of one single, consistent reason why all of those questions are unanswered-- because they can be provided via software, and Apple is unsure about whether to provide them (or at least whether they will be included in the release version).
In most cases, the best clue comes from what has been done on the iPhone...
Can you save and transfer documents to the iPad? Document live within Applications. No shared filespace. So yes and no.
Does the iPad support Microsoft Exchange email? Yes.
Does the iPad support VPN? Yes, but some features aren't done.
Configuration management? Yes, for corporate customers, but some features aren't done.
Real Programmers don't eat quiche. They eat Twinkies and Szechwan food.