Doug "tigerdog" Shelton has released builds of "Firefox" 2.0 for BeOS and ZETA. I say "Firefox" as, due to patches being required to the official source tree, these builds cannot be branded as Firefox for trademark reasons.
Available
from the Bezilla Blog, the builds are, as always, for R5.01, BONE and ZETA; and are from the official 2.0 source tag, with two minor patches for BeOS-friendliness.