I think the thread title's accurate: Disney announced the Fantasyland rebuild one day, then Universal has this mondo videocast to reveal details and pin down an approximate opening. Was it only a day apart though? I won't nit-pick because I frankly don't remember the time lapse.
Universal's been pretty closed-mouth about the HP Land details, especially the timing. Instead of 2010, it's now "Spring 2010."
I don't blame Universal for not putting a date in stone. It's difficult to hit a date with all the planning and construction. Disney did the same thing with the Hall of Presidents reopening. They didn't name an exact date because if they had to delay, people who made travel plans just for to see it would be angry and disappointed.
I think the timing of the two announcements are a little bit "coincidental" and a lot "well-educated guess." It's Fall, and many people are planning next year's vacation schedules, so both companies want to get their attention.
The
D23 event was well-publicized in advance, and many fans and pundits expected Disney to announce something big. Universal was smart to ride their coattails and announce the HP update right afterwards.
As an HP fan, I fully intend to check it out, but I think I'll wait until late 2010 or 2011. We haven't been to Universal in many, many years, and I'm not a roller coaster enthusiast. I'm more interested in the theming, shops, and sites. I would expect Universal to open with a few new attractions and lots of new landscaping, but they'll probably finish up their plans later. Patience can be rewarding - just think about how the Magic Kingdom grew after opening.