Things I'm looking forward to in the season finale:
1Action sequences that end disappointingly because Amon is gonna get away because it's only the first season and there are going to be like two more of them
2Asami being angry even though Makko wouldn't leave her for Korra and he only carries her when she faints and watches her when she sleeps because he lost his parents when he was little so now he takes on the role of parent with other people.  Ok, I'm willing to admit that Makko did those things in part because he sorta likes Korra, but also people fall into roles from very young and can't shake them no matter what.  I have first hand experiences with this, my older sister acts like everyone's older sister and I act like a younger sibling with my friends who are older siblings.  Makko has had to act like a parent from very young so he does that with Korra when she's in trouble and he always acts like that with Bolin.  Asami sees everything Makko does with Korra through the lens of "Makko kissed Korra once", but she's understanding his actions incorrectly.  
3Lin still being badass.  Her bending is gone, but Asami and Amon are nonbenders but they kickass.  I don't think Amon knows the long term effects of taking peoples' bending, because unless he learned it from Aang, I'm hoping he's doing it wrong and Lin's bending can come back.  
4Amon being a really honorable and respectable villain.  Seriously, Amon is my favorite villain ever because what he's doing is arguably bad, but the way he's going about it is really smart because he's not a dick for no reason.
5Korra talking to Aang and maybe other past avatars because a season finale is always a good time to have a spiritual breakthrough
6Korra airbending for the same reason as 5
7Pabu and Bollin being comic relief and also having badass moments
8Tenzin and family doing things because I should mention them
9General Iroh existing, I don't really know what to expect from him because all I can think about is how much I miss Zuko and how irritating it is that everyone who didn't get together (Toph and Aang, Katara and Zuko) had children who did get together.  I guess Iroh is going to be badass, but everyone else already has a monopoly on that so I don't know.
10Backstory on Makko and Bolin.  Also Korra because most people find out they're the Avatar when they're 16 and she found out when she was like three or something because she was already bending everything all the time forever. I don't know if this is backstory, but I want to know more about the adult life of the original Team Avatar and their other kids.

Well, that's it.  I don't know if they can get all that in an hour, but they still have another two seasons to deal with all this stuff.  Also I've been writing this for almost an hour so I should probably change the title but I won't.