Spoiler Level: High
The Earth-2 Lionel Luthor finally makes his move, seizing control of Luthorcorp and uniting with Lex's young clone. Lionel starts out trying to pull his usual smarmy double-talk, but luckily no one buys it for a minute so he resorts to just being straightforward for the rest of the episode. Which is good, because we know this Lionel is totally evil, so as a viewer I'm not buying it either. The whole "I care about my family and I want to make amends" shtick doesn't really work with Lionel-2, because there's no way to believe he might be sincere on any level. I can't blame him for trying because, after all, he is Lionel Luthor, but I'm glad he quickly gave up on it. Seeing Lionel and young Lex standing united as flat-out bad guys was much more enjoyable.
Similarly, now that Chloe's back Tess feels like a lost character again. She starts off being distrusted by Lois, which I felt was pretty unfair of Lois since she knows at this point that Tess is at the very least on Team Clark and at most a member of the Justice League. She's caught with her hand in the cookie jar (or more literally with her hand in Clark's trunk of Kryptonian knick-knacks), giving Clark a guilty look when he catches her doing it. And then there's the final scene, where Clark, Ollie & Chloe re-open Watchtower (again) and Tess is nowhere to be seen, because she's busy deciding whether or not to kill Alexander. It's a shame, because she was doing so well the rest of the season. Although she does have that great moment where she tries to show Alexander that it's never too late to turn to the light.
It's great to see Martha Kent back again, and seeing her champion Clark's cause from the political angle. And it's even better that she's inspiring Clark to take those final steps to becoming Superman-- it looks like the glasses are going to be coming for good next episode. In the Silver Age version of the Superman mythos Clark has outlived both John and Martha Kent, so with Smallville being down to their last 10 episodes Martha is no longer bulletproof, which helps create some real drama on whether she's going to survive or not.
So all in all, while it really wasn't up to the quality of the rest of the season, it certainly had some very good moments that I've waited a long time to see, and was enjoyable overall.