I'm mostly happy about people switching from IE (particularly its older incarnations) to anywhere, than from Firefox to Chrome ;-)
Personally, I have been using Chrome and Firefox both. Firefox being the primary browser for browsing the wild web and Chrome for development and for using Google's services.
Back in the Firefox 3.6 days, Mozilla was beginning to get a little lazy, somewhat like Microsoft in the IE6 days. Then Chrome came along and Mozilla realized that they had to compete. It took them a couple of years to catch up, but now Firefox is a worthy competitor to Chrome and vice versa.