Chrome just became a serious browser for me with the recent addition of extensions/plug-ins and alpha Roboform support. Recent market share statistics* put Chrome at just under 7% -- roughly 27% of Firefox's current share. I predict these breakthroughs will cause Chrome usage to grow exponentially over the next few months. In fact, I'm using it now!
*
http://marketshare.hitslink.com/report.aspx?qprid=0