I also suspect Bent will go in January, but not because he can't fit into Lambert's system, more because he won't be happy not being first choice. I agree about Weimann I think he's going to be a top player. But Gabby? His "movement" about a hundred miles from the area is one thing, but anywhere near the box and it's always been poor and not a patch on Bent's. With his recent goal record he barely deserves to be described as part of a "strikeforce".
The problem with Gabby as well with Bent is that they won't fit Lambert's playing style. Gabby is more suited to play for counter attacking side, and I wouldn't be surprised if MON would try to sign him and I think he could flourish for Sunderland.
You all might find this harsh, but I hope he isn't injured badly as I want him gone in January, for as much as we can get.