The Patriots did what they always do. They assigned a value to Welker. Last year they offered 2 at $9m per year. Given the hits he takes, the wear and tear on his body, and the league's continued crack down on concussions (of which Welker has said he's had several), I can see why they would offer him the deal they did. They would not go more than two years this year, they would not guarantee the entirety of the deal like Denver reportedly did, and they stood firm. I wanted Welker back, I don't think any one player will replace him, but they have moved on.
With Amendola and Jones signed, Lloyd restructuring, and possibly signing Emmanuel Sanders to an offer sheet, it looks as though they are going through a sort of transformation at the wr position. This is what they did with the backs and tight ends as well as the linebackers and de's over the last few years.
Oh and John Abraham is finalizing a deal, I just saw on Twitter and Adrian Wilson is in for a visit. This is the team that never stands still, they just wait for the dust to clear.