At least another 2 years. As to the other companies coming back? Topps is a maybe but that all depends on if they like/can afford the package the nba will put together at the next negotiation. Upper Deck... likely not. From what I've seen of their (minimal) releases of late, they seem to be clearing out all of there remaining GU's/ Sticker autographs so my guess is Upper Deck will not have the cash for a new contract. They are barely keeping their heads afloat in the college market.
forgot to add, upper deck also seems to be selling up some of their acquired licenses. Hoops was skybox, then Fleer then Upper deck and is now Panini. Marquee was a one off for fleer and now that's panini. I just hope panini hasn't acquired the license for Skybox from upper deck or - if they have - they don't release a product under that name. It was death knell for Skybox, for fleer and then for upper deck.