I personally don't think the Zune 80 debut was so much of a "controlled release". I think the Zune marketing dept. botched on this one with their projected sales. Don't get me wrong; I too thought that the Zune 4 & 8 would be a huge hit- with it's wide variety of colors and lower price would have made it more inticing, but that Zune 80 is just too dang sexy to not want.
NPGMBR, what you're saying does make sense to me, but what I have seen in all the store (still today) are an over-stocking of Zune 4's & 8's. Here in Houston there was an average of 2 Zune 80's per a store, and 0 for Best Buy (they really screwed up that one).
On the other hand, if they palnned on a limited debut release, and then made plenty available just in time for Christmas (say, Dec 17 or so) - that's brilliant!
On a side note: 3 weeks ago a radio station had mentioned an article that reported on the low demand of MP3 players for Christmas this year, since "the entire world" already has one form of an iPod. I was a little peaved that there was no mention of the new gen.2 Zune.