To answer your first question, yes this is a superfight. Jose Aldo vs. Frankie Edgar is the best possible match in mma at any weight class below 155. This is going to be the eighth title fight in a row for Edgar, and the sixth for Aldo. A long time ago, in a galaxy far, far away, after defeating BJ Penn to win the UFC lightweight title, Edgar was asked at a pre-weigh in Q&A session with fans who he'd most like to fight out of anyone in the UFC or out. His answer was Jose Aldo, who at the time was the WEC featherweight champion. The two organizations hadn't merged yet, and Aldo would have been the stiffest competition outside the UFC. Fast forward three years and Jose Aldo is Frankie Edgar's stiffest competition in the UFC.
Edgar is perhaps most famous for his resiliency and his ability to come back from the brink of defeat, further defining what the brink actually is in the process. Both of his fights with Gray Maynard featured exchanges where Edgar was being bounced back and forth around the cage by hard punches early in the fight, and in both fights Edgar came back and kept fighting. Aldo is most known for his amazing striking, and sheer dominance. Aldo lost his way a bit at UFC 129, when he gassed out against Mark Hominick, but he already had enough rounds in the bank to win. Other than that he has looked almost perfect, never really being in danger of losing.
Jose Aldo will most likely try to impact Edgar's boxing by chipping away at him with outside leg kicks. I don't think it would be wise for Edgar to fight at range against Aldo, as most of the champions strikes are thrown with fight-changing intent, and that combined with his aggressive finishing instinct usually make a short night for the challengers looking to strike it out.
Shooting for the takedown in the middle of the cage against Aldo is a very effective treatment for insomnia. You will be sleeping tonight. That's not to say that the pressure needed by Edgar to control where the fight goes against Aldo is any easier of a task. Aldo is most dangerous in first round, where he posts most of his finishes. Edgar's best chance is get Aldo against the fence, and try to get the takedown. Aldo cuts more weight than Edgar to get to featherweight limit, so he'll probably be the bigger fighter in the cage. This will be Frankie's first fight at 145, usually fighting at 155, closer to what he walks around at. That could play a factor in the fight.
If Frankie can't get him down, he's going to need to tire out the champ against the fence for as long as he can, and get the fight back against the fence and try again. Aldo has so many more paths to victory than Edgar does in this fight. These two have to be considered each other's most skilled opponent. I see the champion retaining, by second round tko. I think Edgar can weather some hard shots, and his foot work will take fight out of the opening round, but I don't think he'll last against Aldo's onslaught. This is a fight that has been talked about for a long time, between two of the pound-for-pound best ever, and we're finally going to get to see it.