I checked some of the monitoring stations, http://www.seis.utah.edu/helicorder/heli/yellowstone/Uuss.YTP_EHZ_WY.2008123100.gif for example. The background tremors seem to be picking up, but it might just be wind, as a front recently passed through. I think I'll be watching this one for a few days.

I noticed that too, and the local distribution of the cluster does look somewhat like pre-volcanic activity. But if it were the supervolcano. I'd expect activity along the caldera margins. This looks more like something that would result in a new cone or maybe just some new hot springs under the lake.