slammie, the principal sounds like he is either very over scheduled, checked out, or possibly his administrative staff isn't organized well and they dropped the ball on notifying you that the principal wouldn't be able to meet with you. It's also possible he's a hands-off principal who expects his lead teachers to take care of program details.
From what you describe of the school (if I understand correctly, the full school is a gifted/high achieving magnet but the program your ds qualifies for is an accelerated program for highly gifted students within the school). Whether or not the principal is totally checked out, this program sounds like it has a lot of potential positives associated with it. I wouldn't worry about how they actually accomplish subject acceleration until you've had a chance to ask and see it first-hand. That's not because I don't think it's important, but rather because I'm guessing that with a program geared to HG+ kids, they've got something in place already. The other positive would be classroom peers - even though there are "two HG" kids at the private school, if this program has high bars for admission based on ability and/or achievement testing, then your ds is guaranteed he'll be in a room of either high ability or high achieving students.
The flip side of this is that the private school may be a great solution also. Have you talked to any of the parents who's students attend it? I would ask the principal if he could have the parents of the HG kids he mentioned contact you and tell you about their experience. You can also ask if they'd let your ds attend for a visiting day to see what the school is like.
Hang in there!
polarbear
