Went on Saturday. Still a bit of teething problems, and not all of the booths are open yet (including the frites and beer stand), but lots of good stuff there. Not cheap though (about 7-10 bucks for the various sammwich options), but a lot of good choices. Think most everything should be open by the 15th.
I checked out the Vietnamese stand and got a Banh Mi. Delicious, but not very large. They didn't have pho yet, but should be up with that in a week or so.
Definitely what Hawk said - not everything is in place yet and it is pricey. Pretty neat place though. One of the butchers had a blonde girl working there with massive hogans. That was worth the trip alone.