Just a thought. As I write this, we are days away from the trend-making interactive, music and film fiesta-val that is South by Southwest (SXSW). I've never been (I seem to always have a conflict) but like you I'll be able to follow along the "backchannel" by monitoring Twitter. I fully expect that come this weekend, "SXSW" will be a trending topic on Twitter, and will likely stay there for days if not weeks.
If you agree with that (and if you don't, by all means say so in the comments), you then have to ask yourself why that will likely be so. Is it because SXSW is so globally important? Or because Twitter's reach far exceeds its grasp? I think you know the answer to that question.
I certainly don't want to come off as a curmudgeon here--I use Twitter daily--but consider this: very soon, as the darling-of-SXSW mantle is passed from Twitter to Foursquare/Gowalla and Plancast, your Twitter stream is going to be polluted with people checking in as "the mayor of Austin Convention Center" or getting swarm badges at Stubbs. If that is in fact what you see, it's a sure sign that you need to broaden your horizons a bit. Twitter is what you make of it, and it is a poor potter that blames the clay. So when you get sick of SXSW tweets, remember that the Twitter selection bias is easily preventable.