Everyone hit all the high points about rogues/vigilantes here, so I'll only add this:
I24 had added the first Rogue and Vigilante contacts/story arcs. There were, if I recall correctly, one generic contact of each alignment (from whom you could get tip missions), and one story arc contact of each alignment. I don't recall a lot about either, as I only ran through them once each on test, but one of the two was decidedly more lackluster a storyline than the other (it was on par with the Villain intro story arc "Hearts of Darkness" which was very silly IMO; I believe that both were written by the same dev). I have not yet hit 20 in-game so I can't say whether those contacts were retained in I25 or not.
From what I recall of the developer's notes on future plans beyond I24, they were also going to add Rogue and Vigilante stories in Khallisti Wharf, and the I24 contacts were sort of an experimental attempt to gauge interest in developing more alignment-locked content for those sides.
Personally, I found it to be a really interesting area that I would have loved to see more exploration of, but I'm an avowed fan of Praetoria and the Loyalist/Resistance story arcs. Ideally, I think it would be great if both "Red" and "Blue" sides were somehow able to be better incorporated to allow play across alignments for all levels (or even just post-20) but that of course would be a very large project and something that was not on the radar for the Paragon Studios developers at any point.