I dont want to cause too many waves here, but one theory is that Boldin was simply the only offensive threat ARI had last yr and so they called his number over and over thus inflating his numbers. With a 2nd WR there logic might conclude that they will share yards rather than all of them going to one player. Maybe, just maybe, Boldin isnt as good as last yrs numbers might suggest. Personally, Im probably not going to pay the ransom he will demand in most drafts this summer.
As for the Lions, I think Williams will have the better yr unless Charlie can show he is 100% going into the season - and as of now he's still rehabing. A couple yrs from now? Thats simply a toss up - but let me go with Rogers.
Which tandem is better? Ill go with my homerism and say the Lions if nothing more than a case can be made that each was the top WR coming out of college. Also, theres the QB factor, and Ill take Joey over McCown.