Spoiler Level: High
Wow, this show had so many cool fanboy moments I barely know where to start. Not only do we get Lois & Clark's Lois Terri Hatcher playing Smallville's Lois Lane's mother, but we also get Supergirl Helen Slater playing Clark's mother Lara in the same episode! And as if Granny Goodness and her Female Furies weren't enough, we get a bonus bit with Desaad and the return of Godfrey, setting up for Darkseid. (And hopefully Apokolips!)
And in another interesting twist, we discover that Tess Mercer is actually Lena Luthor. Well, okay, Lutessa Lena Luthor. For me, this actually felt very right, and only serves to increase her finding her place as a character, and is probably a step they should have taken from the beginning. She was introduced as a replacement for Lex when Michael Rosenbaum left the show, her name being a tribute to Luthor's sidekick Miss Tessmacher from the movies and Luthor's bodyguard Mercy from the comics. But it felt like they were never quite sure what to do with her; she's a bad guy, then she might be a good guy, no she's a bad guy, she's a Checkmate agent... now she's a former Luthor, a tortured soul abandoned by an evil family, trying to make amends for the bad things she's done in her life. This is a very good angle with a lot of options.
And lastly, this episode inspired me to make my first Smallville LOL.