There are other tabloid sources around, although none confirm it as true.
I wouldn't be surprised if it is true though, TV Burp has been going a long time and it isn't quite the show it was when it began, its not unfunny but I wouldn't be surprised if Harry wanted to do something different.
He's been talking of being tired of it for a while, but also that he wouldn't want anyone else to take over for fear that it wouldn't be as good.
Recording for the new series is (was?) due to start next Thursday, and I've seen signs for a TV Burp production office in TV Centre already. He was on Iain Lee's show on Absolute Radio last night - in which he mentioned that he would start writing for the new series on Saturday.
What it sounds like is that the upcoming series will be the last. Not that confusing really. It's been going for the best part of a decade, so really, it's had a decent run, better to go out on a high.