Frank just fought in the first-ever scantioned MMA event in California, winning over longtime rival Cesar Gracie by KTFO in round 1.
He's also announced that he's going to reenter MMA competition.
The thing that really kept Ken from being a real danger in the early UFCs was that he kept breaking things (ankles, wrists) and being forced to leave the tournaments. If you go back and watch, he and Royce were really being promoted as the two "heroes" of the org.
Ken's fight against Tito was his first after coming back from the WWF and he claims that a knee injury kept him from doing anything except standing and banging which was his downfall. So, saying his time in the WWF was responsible for his popularity isn't strictly true. IIRC, his excuse against Franklin was that he went down two weight classes and didn't have any energy.
But yeah, he's way past his prime. Hell, despite his complaints of the fight being rigged, the KO by Sakuraba was embarassing (and if you watch the tape, the ref made the right call, although it was eerily reminiscent of Sakuraba's first match in the UFC).
Hell, in Pancarase, he beat Bas Rutten - twice!