Not trying to "rain on peoples parade", but both TGM and UG give
all of June a similar rating as they did to Spring Break. The Easter crowds will also be thick.
I know that not all schools are out by the first week of June, but I don't think you should expect parks to look like those pics from the first week of June '05. They're gonna be a lot more crowded. I know there are better hotel deals than the 4/3 that Disney offered, but a lot of families who wanted to stay on Disney property before could do it now with the 4/3 deal. And so they booked. My week in June was booked solid when I tried to change my trip by one day last week before the deal expired. I couldn't change my trip because there was no availability for my week. I know this doesn't mean all the hotels were booked full. I know it means only the rooms available to book under that promotion were booked, but that's still a lot of rooms booked.
Then, you have Space Mountain, which usually gobbles up a large segment of park population by luring them into its ever-increasing line, under rehab. Where are those folks gonna go? Oh, snap! To all the other "thrillers" at MK, making
those lines longer. Also down are the less-popular Hall of Presidents and TTA. While not nearly as much of a population gobbler as SM, those folks that would have been in line for them will also be in other lines throughout the park.
I am going expecting both TGM and UG guide to be wrong about their predictions and for it to be more crowded. I am planning my trip as if it will be wall-to-wall people.

Then, if it's anything less, I can be pleasantly surprised.

My last trip was during Mardi Gras '08. Now that's a beautiful time to go! (As long as it doesn't fall on the same week as President's week like it does next year.)
My boss and her family just returned from a week at WDW. She said all of the lines, even the lines for the less popular rides, were packed. She told me to fully expect June to be scorching hot and crowded.