First, thanks so much to Len "Cassandra" Testa for making a good faith effort at providing us with some guidance (heh, "Guide-ance". I crack me up!).
Second, in case anyone's missed it, Disney is having some little get-together called The Happiest Celebration on Earth! Even here in AZ, we've been bombarded with print and TV ads for WDW for months. And the date that's been pushed and pushed is May 5th. How can anyone be surprised that crowd estimates will be higher than typical for this time of year?
Third, liveforthemagic, you said "I am taking my kids out of school a week and a half early to benefit from the Level 3 crowds..." I'm certain that a lot of other families are also doing this, too.
Fourth, dcibrando said "those that were planning on going to Disney this year aren't necessarily going to change their reservations to May for the Celebration when it lasts all year long!". Not sure I agree. If I were planning on a WDW trip this summer, and heard about this massive Celebration, the first thing I'd think is "Boy, this summer's going to be NUTS!" and I might indeed either move up (May) or back (Oct-Nov) my WDW plans.
Finally, DW and I will be there (SOON!

) from 4/29 - 5/6; our 25th wedding anniversary is May 2 - and that's a date that was picked, oh, about 25 years ago! The crowds will end up being exactly what they are, and while Len's good advice might help us mitigate them, we can't change them. But we're still going to have a great trip! <insert "Serenity Prayer.doc">
Be well!