Lille won't be in a hurry to sell him, because Lille don't own him Arsenal has to seal the deal before the Euros or we'll most likely lose out on him. I think the player would also prefer to sign before the tournament starts, so that he can put full focus on succeeding with France.
He has already decided on Arsenal but there has been no offical contact made... that will be done tomorrow. The deal will be done in about a week. He will definitely be an Arsenal player though.
Tribal football is an awful source. This bloke seems to be quite reasonable though: https://twitter.com/#!/BFairthorne
He says agents have spoken this morning and deal will be tied up soon - though not complete yet. Seems pretty confident but you never can tell.