We looked into the various programs and ended up putting our daughter in a Waldorf pre-school several years ago. We looked at Montessori, but didn't like any of the ones in our area.
Partly it depends on what you're looking for. Waldorf HEAVILY bases on play-based education - there's lots of songs, stories (not read, but 'told' from teacher memory) and interaction amongst the kids. If your goal is a creative kid who interacts with others and can really use their imagination - or if you've got one of those already, then this is the way to go.
Couple of side notes: they don't push reading until a little later than regular programs, but I didn't see that it hurt much. I met many of the older kids and even an alum who was at York High School and they were all reading way above grade level; the ninth grader I met was reading "Reviving Ophelia" and we were able to discuss the book with depth. The school teaches the letters gradually and in such a way that the kids can KNOW the letters - I heard one teacher tell a ten minute long story about the letter K, shaped like a king, etc. Same with numbers and shapes. If you're really just shooting for pre-school, reading shouldn't be that high of a priority as they really get lots of that in kindergarten.
The schools also tend to be dead-on serious about food concerns and issues, and my vegan daughter was accommodated, as well as the kids with nut allergies, wheat, etc.
However, as noted by another, Waldorf is also a culture. There are plenty of pro and anti Waldorf web sites out there to discuss it.
(As a former teacher, I can also say that just by being concerned about pre-school education, you're setting your child up for success early. When they see what you value, they learn to value it as well.)