Unfortunatly, I would not expect that
Total War: Warhammer would have any positive effect on our game. Actuall, given that GW is in the process of totally revamping their fantasy setting I'm not sure how much benefit Warhammer Fantasy is going to get from the computer game tie in.
From what I've heard, GW's licence for the Jackson/Weta/New Line stuff runs through the end of next year. I would expect them to keep something in production until then, although they have already stated to let some miniatures go OOP. If there is a particular faction you want to collect that is still available from GW, I would probably try and pick that up sooner rather than later.
You seem to be able to get anything from the LOTR stuff fairly easily on eBay, although you will pay a premium for some of the more rare figures. The newer Hobbit stuff shows up on eBay too, but its not as common since there seems to be so much less of it available in the second and third party market. I guess if you can probably figure on finding anything you want for the next couple years, if you are willing to pay for it. As time passes and once GW drops the game altogether "offical" figures will get harder and harder to find.