The first game probably wouldn't work, but Beyond Divinity could have benefited from a two-player co-operative mode. I'm not a fan of multiplayer myself, but I can see the interest in it.
If anything, this would be a major patch. Getting network gaming to work can be a real hassle. Larian have obviously put this idea on the back burner until the more pressing problems are sorted out.
Multiplayer is coming in Divine Divinity 2, so your wish is coming... <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />