I wonder if it would've been better for MS to continue allowing preorders on items that "ran out" but add a big ol' warning text that the shipment will be delayed with an estimated time. I suspect some people would have been satisfied just to get their hand in and order the darn things and be done with it, rather than keep checking, even if there is a delay. Some vendors do this--if it's in stock, it'll ship in 3-5 days, but if it's "temporarily out of stock," it'll ship in like 3-5 weeks.
For those looking for some color, Best Buy in the US (or at least Arizona) now has the Cyan and Magenta available for pickup immediately in some locations. I placed an order for the cyan type cover 2 earlier today and got my pickup notification about an hour later. Going tomorrow morning to pick it up.