Red/Blue/Green were remade when Pokemon went to GBA.
Gold/Silver/Crystal were remade when Pokemon went to DS.
RSE could very well have a remake since we now went to 3DS. And it will probably be Emerald remake just like Crystal, but they would probably follow the Ruby/Sapphire naming.
I don't think there would be a sequel. There is really is no point unless they make a new team. Which I don't see happening. I just find it stupid if they don't make remakes of RSE.
If we get a remake, I think it will be around March 2014.