Cliff: I don't like frame interpolation for film at all. Would never consider using it for a second for film.
For TV, I think it looks 'strange' mainly in the sense that it is different and unusual. It varies depends on implementation, I'm most familiar with Samsung LCD's flat panel implementation, which I don't think is the best out there, so only judging on this particular implementation I find it a bit hard to get used to.
It does/would reduce the kind of motion issues that you get with a sample-and hold like an LCD, but then everything looks radically different.
That all being said, my benchmark is accuracy, and it's a VERY different look and feel to a film, which is why I never ever would consider using it there. I don't feel the same thing about TV, but then I don't really watch TV except CSPAN, so needless to say I don't care a whole lot about what stuff looks like on TV.
So in the end, I think it's intriguing, and I'd love to see a really high-end and well executed implementation of frame interpolation, and I can see it being very useful for certain specialized tasks (virtual reality, simulators etc) or content, but it is a drastic departure from the look of the content as it was created that I'm interested in, thus inaccurate. And in my book, inaccurate generally always equals bad.