I had heard on here that Morrowind on Steam doesen't allow for mods/modding, and what not.
If that's true, I definitely won't get it.
I just noticed it because a few days ago we got Broadband (after dial-up for 11 years) and Steam has it for a slightly lower price than the Bethesda Store.
Besides that, I guess I prefer to own boxed copies rather than Steam. Just in case, someday, the internet implodes or something...