Well, if anyone didn't know your feelings about NDAs before, I guess they know them now!
Without exactly disagreeing with you, I would like to make a couple of clarifications...
NDAs tend to be something imposed on product managers by legal departments, not something that the product manager dreams up as a keen idea. PSC's legal department has rather tight-a**ed attitudes in a number of places, so it isn't surprising that the want NDAs all over the place to cover their a**. But, it isn't really fairly to beat up the product managers about it.
In practical terms, it also isn't much of a constraint. Significant new features of pending releases get talked about at Exchange and thus are previously disclosed material, which they can't control. The only time I have had them ask me to retract or correct something was when I posted a handout from Exchange ... but then, it was their copyright material. Stupid perhaps, but within their right.
Now, I can see why you would think that your not having the beta was PSC's loss, but I suppose you can also understand that they aren't likely to see it that way. Pretty hard to deny that you lose out on the early exposure though. Given your fondness for ChUI, I don't suppose that you have a lot of interest in ABL for .NET, so that isn't much of a loss either way. All I was trying to point out is that PSC gets to make the rules here and one should recognize that the consequence of refusing to sign the NDA is to not get to play with the toys.
One might also note that there wouldn't be a lot of point in MSFT having every beta user sign and NDA ... if you hand out that many copies, someone is going to talk somewhere, so why pretend. You want to bet, though, that they use NDAs too and are quite serious about it when they aren't flinging software across half the known universe.
My remarks about the schedule have nothing to do with NDA. The point is not that the date is determined, but secret. The beta participants don't have a date either. The point was that they have a target window, but they only set a firm date after the cutoff and gold build. Before then, there is nothing to keep secret except some vague targets on a planners calender.