I agree with Deus. Edelman didn't do much last year--despite what some seem to think. That said though, he did show flashes and is obviously very talented with the ball in space.
I think he's an excellent punt returner, and is definitely able to turn some bubble screens etc into nice gainers with his YAC abilities. He does have knowledge of the system of course, so it's good to have that. The thing I appreciate about him the most I think, is his ability to take over for Danny Amendola should he go down for any length of time. I am a firm believer that our bread and butter will still be utilization of the slot and the quick timing passes, so I'd feel a lot better about having Edelman on the squad to take over that role should it come down to it.
It's pretty obvious that he lacks the proper tools to be an actual outside wide receiver, at least at this point in time; hopefully he can improve in that area because I do think that he offers some nice attributes that the team can take advantage of.
I'd certainly feel much better if he were here this year, than if he were gone.