Well, you couldn't combine two more rabid and loyal fan bases if you tried. If Lego does this right, and makes a good, detailed castle with a nice interior and perhaps a Walt Disney mini figure, I don't think the price is going to matter. I would personally rather see them go towards the upper end of the spectrum and give us a set with at least 2,000-2,500 pieces. Again, if it is done right, I would shell out $350-400 for it.
In case you didn't know, there is a deluxe suite inside the Cinderella Castle at WDW, as well as a dining hall area. Both of these could be represented in the set.
I can honestly see this as the beginning of an entire line of Disney theme park sets. I mean what Disney fan wouldn't want a haunted mansion set complete with a hatbox ghost and hitchhiking ghosts mini figures? Or how about a WDW railroad train set? Perhaps a Main Street USA series of modular buildings? I know this sounds far fetched to some, but I think the power of the Disney fan base is being under estimated. Lego is testing the waters here, and time will tell how this all plays out. I for one am extremely excited!