She also revealed some more general snippets of information, including:

Aberforth Dumbledore is the barman in the Hog's Head
Dumbledore's patronus is a phoenix
Grawp will be more controllable in the sixth book
We will see a bit more of Rita Skeeter
There will be a NEW CHARACTER called McLagan
Harry does NOT have a godmother


So, I'm kind of wondering what part of the story McLagan will play. I don't think it sounds like a childs name, so I'm assuming it isn't a student of Hogwarts, but then again, I may be wrong, you never know.