Yes, this would be the worst possible outcome to the Wes Welker situation. According to ESPN's Adam Schefter, the Denver Broncos are in "serious discussions" with possibly soon to be former Patriots wide receiver Wes Welker:
Filed to ESPN: Broncos in serious talks, trying to hammer out an agreement with Patriots WR Wes Welker. Decision expected today.— Adam Schefter (@AdamSchefter) March 13, 2013
The Broncos, along with the Ravens (although maybe not with their roster overhaul), are widely considered the biggest threats to the Patriots in the AFC in 2013. Giving them their Hall of Fame quarterback the Patriots' Hall of Fame Quarterback's favorite target would certainly provide an edge to the Broncos.
Until this is final, we can hold at hope that it won't happen. And regardless of whether or not the Patriots can replace Welker's production, he is worth signficantly more to keep him away from the Broncos and Peyton Manning.