Meh, don't believe anything until you hear it from Gaga or the label themselves. There's way too many rumored dates floating around the press that don't match with each other.
I don't think that she'd release it that late, the tour ends in March, she may "rest" for what one or two months and release the single around late june/early july then album in september, at least that's what I think.
Noooo, here's the link, it was published 11 days ago, looks like it'll be fourth quarter afterall I still think we're getting a single on 29 June though..