If the current Post-RotJ is any indication, any and all reincarnations of the Sith will only be broken fragmented shadows of the real Sith line that ended with Reborn Palpatine, not for a very long time will we see Sith even a percentage the strength of the Banite line.
Oh and for anyone who says 'Caedus' he was the last hope for the Order of the Sith Lords as a proper force, unfortunately for the Sith, Lumiya and Vergere didn't remove his love for his family, much the same failure as suffered by Sidious, as Sidious was 'killed' by a redeemed Anakin, Caedus was figuratively killed by Jacen's love for his own family.
The Sith are basically finished, a few organizations will pop up here and there, but nothing of true significance and sustainability.
Will this change for the Sequels? I am going to guess not, especially if Lucas has anything to say about it.
You know this actually might happen. The part about the Enemy being broken fragmenets of the Sith.
Especially since according to The Hollyword Reporter, Arndt is highly invested in the SW Mythos.