I signed up for Clearwire in mid-November & never lost service--even through the most severe storms. Several of my friends who have Comcast and/or Millenium complained of outages during this period as well.
It's easy to use & I get a really strong signal all of the time. The modem has a rather large footprint at the moment, but they are providing smaller models in February (last I heard).
I have recommended this service to lots of folks & for each person I refer, I receive a $15 webcertificate. :)