There is no possible way Disney would "advertise" a seasonal promotional package with an extreme limitation on rooms. That just seems like a huge public relations nightmare (of course led by Brerdad). I mean honestly... think of how rediculous that would be. It's April 12th the first day of a 3 month booking period and by 10am 90% of pacakges are already gone?! Disney would have to have some set of kahunas to pull off a stunt like that.
Plus keep in mind... that this is not an exclusive Disney offer. USairways and AAvacations are also advertising the promotion and I'm sure there are several other travel sites that will show the offer come the 12th.
I have a gut feeling that Disney Visa card holders got "left overs." Meaning that once Disney set aside public packages and "partner" packages they threw together whatever was left over and offered it to Visa Card holders. plus this helped ease the rush Thursday morning. Some who booked with Disney Visa had to change resorts and travel dates cause their's were "sold out." I bet when Thursday rolls around the "public" will have no issue booking there desired resorts and dates: Disney Visa 0 - Public 1
As for pre-booking with the hopes of free dinning: It seems that alot of people had the same idea "book my room now, add free dinning later." The only issue with this is that it "inflated" bookings... and "could" have limited the amount of packages Disney decided to offer. Just a different way to look at I guess...