Seems a very strange choice to me. Even if you specified that the host was going to come from the British Isles, I doubt Kielty would have been in the top 50 most logical choices. Top 100 probably, top 50 probably not.
The guy is pretty good at what he does; he can ad lib acceptably well, he has a reasonable sort of stage presence, he is used to the big occasion and he knows how to show empathy. However, he's very young, especially by USA game show host terms, he's very slight, he's very lightweight. He's really not the sort of person you'd think of as a host for a (multi-)million dollar game show. It's hard to believe he might get to hand a cheque for a million dollars across, he doesn't have the authority. He also has a relatively strong accent; not problematically so - no more problematic than, say, Anne Robinson. The Irish accent might go down better than the British one in the US.
However, the worst problem the guy has is that he is unlucky; his shows consistently do less well in the UK than any logic suggests they should. Admittedly his chat show has lasted six years, which doesn't happen by accident, but has never been a big draw; Pop Idol has always got a lot of attention from the BBC, but I don't know how much credit Kielty can take from it. Oh, and there was The Big Ticket, which is one of the textbook examples of high-profile game show disasters.
I hope it goes well for him, but the omens aren't favourable. Fingers crossed!
