It's only been a few hours of test-browsing, but so far I really like Firefox. The alt-browser seems to use about 10X less memory than big, bloated MSIE. And—wonder of wonders—it actually imported years and years of Explorer bookmarks correctly and quickly.
But there still seem to be issues with Java on some sites that make Firefox react in odd ways. Once I suss those out, I'd be very tempted to deep six Explorer for good.