I don't believe there are any. The BX chipset has been pretty thoroughly phased out.
The Tyan Tiger 100 is a dualie BX board, but it's slot based. The Tiger 133 is S370, but via based. ABIT of course has the VP6, but it doesn't appear to be all that wonderful.
{EDIT]Actually, now that I think about it MSI may have a dualie BX board that's S370... I'll look.[/EDIT]
[EDIT2]Nope, it's VIA.[/EDIT]
Viper GTS