This is normal. Most of the 1,600 or so quakes since January 17 have been very mellow. Yeah, it sounds like a lot of qukes to have happen in a couple of weeks, but the vast majority of these have been magnitude 1-2, and only one got up to magnitude 3.8 (the swarm is the red cluster in the western part of Yellowstone National Park, pictured left. click image to enlarge).
Not exactly the stuff of disaster movies.
Sorry to say, there won't be a supereruption any time soon. Anyone who says otherwise (and there have been a few) is about as well-informed and sensible as the person I once saw at that beautiful park, inching within ten feet of a full-grown bull moose for a picture.
For folks interested in actual science, Erik Klemetti over at Eruptions has posted a chart showing how the tremors have gotten shallower during the course of the swarm. As he notes, it's entirely possible that this is just a minor episode of tectonic movement that's making its way through the heavily fractured crust.
Or it could be an indication that lava is slowly migrating up through the crust, perhaps to erupt in a small dome of material some time soon. The point is we don't know. It will be interesting to see what, if anything, unfolds in the next few days and weeks ahead. A dome eruption (kind of like toothpaste squeezing out of the planet more than an "eruption" like you might picture it) would be cool in that it would add to Yellowstone's unique, ever-changing landscape.
If we're lucky, it might even convince some of the people waiting for the end of days to come roaring forth from Yellowstone Caldera that they're wasting their time.
For the latest updates on the swarm, check out the Yellowstone Volcano Observatory.
Image: USGS/University of Utah