yes, win2k does support dual monitors. i installed a geforce 2 mx400 twinview recently in a dual boot machine running 98 and win2k and the twinview support was amazing in win2k, and only adequate in 98. it worked in both, but it was creapy how much more clean the images were in win2k.
keep in mind that the OS supports dual monitors, but it may have difficulty with drivers for particular video cards. The above card from Gainward (see TOms review) works great. others, i cant comment on.....
ignore everything i say