Jay already mentioned on his zane lowe interview that Nas was on in the studio anyway to meet Timbaland and they all just ended up getting together for BBC
But this doesnt mean anything. 2 years ago people were worried that Life is Good would be filled with Alex da Kid and Kane Beatz records cause he did a song with them or even when everybody freaked out about him working with the Internz.
Even if he does work with Timbo, so what? Yeah he had You Owe Me but You Wont See Me Tonight wasnt bad and probably could have been a single. Plus that track he did in Tim's Basement was alight. Timbo himself has gone through different leaps and bounds and changed his style.
Nas' has always had one supermaninstream producer record on his album and its fine.
Ultimatley he sounds comfy on No ID and Salaam record but a little flash from Timbo wouldnt hurt and I dont think it would be too much of his album's share.
Dont panic and dont find a reason to