Accepted to Princeton via an email just now, maybe they're finally rolling out decisions. Visitation days are : February 15-16, March 8-9, March 22-23. I also got a phone acceptance from Yale yesterday, and they only have one visitation weekend in February as someone already mentioned.
I wonder what the vibe is like if you opt for an informal visit that doesn't fall on one of these visitation dates. The profs probably wouldn't be as available, but you might get a more honest impression of the department...
@coppernanotubes (from a few weeks ago): I got the call from prof Chris Chang at Berkeley, and I'm interested in working wither either him, Arnold, Hartwig, or Tilley.