Nine pages in this thread, and I haven't read them all, so forgive me if I'm repeating something someone already mentioned.
Anyway, so Bahamut is supposed to be Bane's archnemesis in the generic D&D setting. Wouldn't that be something of a lopsided pairing, though? After all, Bane is a Greater God, while Bahamut is a Lesser God. Either Bane is gonna need to be downgraded bigtime, or Bahamut is gonna need to be buffed up.
This, incidentally, is the same issue I have with Torm/Bane in the Forgotten Realms. I like that the Realms view Torm/Bane as archnemesis. What I don't like, however, is that Torm is still sucking wind as a Lesser God. Ah, what I wouldn't give for Torm to lay claim to both Tyr and Helm's portfolios in the 4th edition Realms and getting boosted to Greater God status. It'd be so nice to finally be rid of that interloping schmuck Tyr. Go back to Valhalla, Asgard, or wherever the hell it is you came from, jerk.
One other thing on the subject of Bahamut and Bane. Isn't Tiamat Bahamut's nemesis? Wouldn't it make better sense to pair her up against Bahamut, rather than Bane? Or to get some other god and pair them up against Bane? The way I see it, Bahamut/Tiamat are as tied together as Heironeous/Hextor, but then again, maybe that's just me.