So here's the scoop so far on Noah's Ark:
They have (or at least had last week) openings for next year, so we wouldn't be on a waitlist, which we are for the other two. They also don't require parent participation, which is good because that would be tricky with Sam. The program has a little flexibility; they are a Monday through Thursday program, where you can select 1 through 4 days a week. I plan on doing 2 (Tuesday/Thursday is my preference, but if there are only openings Monday/Wednesday, I'll take that.) The hours are 9-2, so it's a little longer than I had planned. (St. Mark's is reducing Wil's age to 9-11:15, which is hardly worth it.) They have a theme each week, they teach a Bible lesson each week (including a prayer before lunch). While not particularly religious, Chris and I don't object to the kids learning a little about religion.
So, it sounds like a good fit for what we are looking for, at a reasonable price. I hope it feels good when we visit and we can get Wil signed up. That'll be one thing off my plate.
Update: The tour went well and I signed Wil up for this preschool starting in August.