The wallpaper on my desktop is a picture of Welker torching the Ravens for a long run. I'm a fan.
That said, there is a nugget of plausibility in the idea of trading Welker. BB is an economist. He makes valuations of players with absolutely no sentimentality, as we must all recognize by now: Bledsoe, Milloy, Law, McGinest, Vrabel, Vinatieri, Seymour, Moss... all elite players that he's escorted off the roster in various ways. When he feels a player has underplayed their salary cap, he exits them.
Now, Welker deserves to be considered a star in the league, and BB himself gave up a 2nd round pick for the guy. But, here's the inconvenient truth: Edelman could hardly find the field last year because of the depth at WR and the gap between Wes and Julian on the field is not as big as the salary gap. Julian is the better value. Wes will command elite compensation in terms of draft picks, presumably from a crummy team. So, although I cant get excited about the idea, I recognize trading Welker is consistent with BB's MO.
Buy low, sell high.
HOWEVER, the idea of drafting Green as Welker's replacement, however, is not "buy low". An early first rounder at a point where the sky's the limit on Green's potential is "buy high". "Buy low" is drafting Givens in the 7th round or Branch in the 2nd (I remember the reaction to that pick on this board was a very loud "WHO?!?") or Edelman off the street. BB loves filling his roster with guys like BJGE, Woodhead, Arrington, Wright, Neal... undrafted talent with the right attitude.
I think BB would draft Green early if he believes the kid is a once-in-a-generation talent, like Moss or Fitzgerald. That's the only way it feels like value. But, is Green a sure thing? I'm not sure... maybe?