Ivan, didn't we hear the same argument after Moss was traded. "how is this offense going to survive without Moss creating that deep threat and double coverage on him". Everyone was asking how Welker was going to get free without the concentration of the defense going on Moss. Remember this was fairly early in the season, when no one really had any idea what Gronk OR Hernandez were to become, by the end of the season, and into 2011.
The point is, there is no question that Welker is currently the "go to" guy in the offense, especially since it has only had one of the 2 big TE's all season. But in your post, you intimate that if Welker isn't there this offense will suddenly stop being effective. Common sense and past history has shown us nothing could be further from the truth.
Now before you start going nuts thinking this post is somehow insulting your boy, nothing could be further from the truth. Welker is a great receiver. His is arguably the best slot receiver in NFL history. Hopefully someday people will overlook his size and he'll get into the HOF (assuming another few years of good production) But its not an insult to Welker to propose that Pats offense would survive him not being here. Hell it thrived without Brady in 2008. It could certainly be very effective without Welker.