I know that Central has a musical theater program (our high school borrowed the sets and costumes for a musical version of "Cinderella"), but it really is out in the middle of nowhere. A gas station and one traffic light was really all that was there (at least 13 years ago when I was there last). It seems strange that there is a program there, so far away from Seattle with all the musical theater opportunities.
I also know one guy who went to Cornish. I don't know how the program is, but he did end up cast into a bunch of productions around the Seattle area, and he did do a reading of "Feeling Electric" (a.k.a. Next To Normal). But really, those two are the only ones I know that has a specialized program in musical theater.
Xanadu! Can't cry on cue!