The current incarnation of Venom has been one of the fan favorites of the entire history of the character. He’s in a place with a host that he’s never been at before and people like it. Venom is actually relevant again – his is one of the most unique series that Marvel is doing. If Marvel were to take him back to being the big sludgy, gross monster that most people know him as it would be a huge disappointment.
I can’t see this happening for many reasons. Considering the Marvel NOW! initiative is not a true reboot and will leave continuity alone, Eddie Brock can’t be Venom (plus he’s too busy being Toxin). Flash Thompson hasn’t been a big player in the Marvel Universe until now and it would be a bad idea to take a character that no one really liked and now really do like and just get rid of him. I suppose if Marvel really wanted a pre-Flash, Eddie Venom story they could set it in the past (much like the differing timelines in all of DC’s Batman books), but that might just cause a big mess.
Likelihood of happening: With the tease of the Minimum Carnage story I have my doubts this book will be getting the relaunch treatment (Venom is confirmed to be a player in that story).