They definitely don't call people every Monday -- that would be sort of insane.
Last year, they supposedly gave out acceptances once each month, usually around the 15th or so. Since it sounds like most people got phone calls yesterday, I would guess that no more acceptances are going out until November.
As for Houston being fun, I definitely like it so far. I spent the last few years in more of a suburban setting, so it's nice to be in a real city with restaurants and coffeehouses that are open late. As for bars and clubs, there's a pretty lively dance club scene downtown, and there are fun bars all over the city. People are also generally pretty friendly in Texas when you go out, which was a nice change from what I was used to in California.