The answer to this is yes, and the reason why that is, there is no one else. There are really only 2 other contenders at this point...Marquardt and Swick.
Marquardt wouldnt put up a challenge for Franklin, Marquardt is a good fighter but we're talking about Rich Franklin here, the most dominant middleweight in the world. Nates fight against Doerksen wasnt all that impressive, he got the takedowns but blanketed him the entire fight...he also showed his chin is vulnerable as well, Franklin would capitalize on that.
Mike Swick is on fire at this point theres no doubt, however his only remote competition at this point was Joe Riggs, he needs one more fight to earn that spot...if he beats the Crow, by all means he should be the #1 contender...before Anderson came to the UFC I always thought the Crow was the second best middleweight in the business....and look what Franklin did to him.
Anderson Silva is already proven, his past fight were against pretty good competition and he's just an all around good fighter. And thats enough to give him that shot, his fight against Leben? Pft, you put a guy with accurate, powerful punches against a guy that shoots in waving his hands around like an idiot and I can tell you who wins each time...and his knockout against old "Iron Chin" definitely sold his shot...only I didnt expect him to get it this soon.
It should be an awesome fight though.