I would not make this trade. With Tebow being the new starter McGahee is going to have quite a few tds poached. Also, with Moreno getting back in the mix he will have more touches taken away. I think McGahee's stock is declining. Mike Wallace is real good, and depending on how many WRs and RBs are started in your league it could be worth countering to get him.
Forte is half of the Bears offense, and will stay that way the entire season, and though Julio Jones is stealing a few looks from White he is consistent. Plus I still feel like White has a few big games coming his way this season.
I like Forte too much to do this deal. I'd see what other RBs he has to offer to help with that void you would create.
I agree, this is not a good trade for you. Forte right now is doing amazing and the Bears are running their offense through him both through the run and pass. Roddy will come around, he's got Carolina this week which is a good matchup, not great. He's got his bye coming up and hopefully he can get this pesky thigh deal to pass.
I like Forte way more then McGahee, and I still like White better then Wallace, although that one is a lot closer