There was a nerf in the patch today which may have killed swarm kiting
AE kiting has been killed. We can still swarm kite, it's just not very efficient in the higher levels. Don't worry, it's a common mistake.
As far as rogues soloing... they CAN do it, but again, it's not very efficient. It requires specific gear and a little bit of luck (you really need your intimitation skill to work early on).
Rangers can solo animals well once they get panic animal (level 22 I think) and they CAN solo other things throughout their lives, just not very efficiently.
I would suggest you not look for "the best" solo class, but for a "good" solo class that you can solo with when you don't feel like grouping. SOE has made it pretty clear that they want to limit soloing as much as possible now. The bards just got hit with the AE nerf, and like Dirshan said, they aren't the top dogs anymore. That puts somebody else on the top of the list, as both the best soloers and the next most likely to be nerfed.