If they do RS remakes, the way they'll incorporate the Emerald changes is unclear. They were able to add to HGSS everything that Crystal changed from GS, Crystal's only big change was having Suicune play a bigger role; there was still the same story and characters in the same place, and you got both mascot Legendaries. With RS remakes, if they add the story and character changes from Emerald, they'll necessarily be less distinguishable as Ruby or Sapphire since Emerald combines the two alternate stories so evenly. I'm kind of worried that the Gamefreak people will try to stick true to RS instead of Emerald if they do remakes, the way they stuck true to RB instead of Yellow when they did FRLG. =s
If you do decide to pick up an Emerald version somewhere, though, good luck. I haven't been able to locate a Sapphire cartridge. Advance generation Pokemon games are long out of print.