I'm quite bored of IAC to be honest, and have had trouble watching most of this series. I kept forgetting it was on, which probably says how much I thought it was essential viewing.
Perhaps that's partly down to my slight boredom with Ant and Dec. They are pretty good still, and occasionally they can be very funny, but I know 99% of the gags before they arrive now. So my "lol"s at them are quite rare these days. They've almost got a bit too polished at it and are now a bit lazy, rolling out the same old gags.
To be honest though, I can't think anyone who could do the format better, off hand. Alot of ITV2 presenters they used shows how ropey most of competition is when it comes to laughs. Maybe Peter Kay and someone he could play off, as I remember the week he presented the "Big Breakfast" years ago, when he had me hysterics when I didn't even know who he was, but he doesn't need a presenting job these days.