Given the job descriptions which Blizzard had out for a while before this release, I think it's Diablo 1 & 2 which are more likely to find themselves remastered next.
With the Diablo 3 "Retro expansion" I wouldn't really think they are going to do a remastered version too.
Ah, yeah I forgot about that. It doesn't make a Diablo 2 remastering any less likely though, IMO, as opposed to a Diablo one.