Unfortunately this is pretty much a Tech frat-boy event these days. I can't recommend this anymore unless you're 25 or under and don't mind a crowd.
The best beer bar in the Atlanta area is the Brick Store Pub, out in Decatur. Fantastic selection of well-poured beers, and worth a drive from anywhere in the area if you appreciate that sort of thing. They've even got a whole bar upstairs devoted to hard-to-find Belgian ales. Some of the Mellow Mushrooms have an excellent beer selection as well. Unfortunately your beer-drinking options downtown are thoroughly mediocre.
I do most of my drinking at Fado Irish Pub in Buckhead, since I live in the area. It's a very nice pub, but will probably be horrendously crowded this weekend with everybody in town for the tournament. The cab drivers seem to send everybody there. Still, it'll be nice during the afternoons and early evenings before it fills up.