I read this and it reminds me of a question I've asked before, but got no answer to:

"Sorry, we will not be making these types of changes. StarCraft 2 has to be a new(ish) game. We still get a lot of complaints from other fans that it isn't new enough. That we have been too timid and uncreative with the design. According to many, we should not have had any units that were in the original game. So we have to walk the line. Some new, some old and do the best we can with the design and balance within that space. I could imagine down the road making a "StarCraft Classic" that would be broodwar redone in the SC2 engine. Honestly I'm surprised that "StarCraft Classic" hasn't already been made by the fans and that it isn't #1 in Arcade. Could one of you guys get on that? ;-) "

This makes me ask the question again- will heart of the swarm add new features to the editor that will allow for aesthetic changes (as opposed to just statistical changes) to units? This will allow for a complete copy of Starcraft 1, as well as allow mod-makers to make new units for SC2 (and possibly a 4th race-I can only hope for that mod)