Not by Epic, but still.
In an interview with games site Kikizo, Epic Games VP Mark Rein was asked about the possibility of getting some form of Unreal Engine 3 running on Nintendo Wii. According to Rein, one of the engine's licensees is already attempting it.
"I know one of our licensees who's giving it a shot; it's their own port, in the same way Ubisoft brought Unreal Engine 2 to the Wii," says Rein. He alludes to Ubisoft multiple times in his answer to the question, but never says outright that they are the licensee responsible for porting Unreal Engine 3.
As for Epic themselves working on it, Rein says not to hold your breath. "I just don't see a big market there to bring this big hulking memory intensive engine over to a much smaller system." Rein seems open to the technical possibility of some version of the engine running on Wii, but he remains uninterested in the commercial benefits for Epic. "We won't don't do it ourselves. Look, there's so many things we can do, and are already doing, to improve our engine on the platforms we're aiming it at, that going back and working on that [for Wii] just doesn't make sense."
But Wii-owning Epic fans take heart: at the end of his answer, Rein mentions the possibility of creating a graphics engine geared specifically for Wii. Said Rein: "The engine is getting optimized and we're improving it all the time; there's too much low hanging fruit that we already have on the engine side, and new improvements and things we can do to try and make an engine for the Wii - it wouldn't be smart business for us [to port the existing UE3 to Wii]."