Eminem Rejects Offer To Work w/ Lil Wayne?

Hip hop fans (especially those on the internet) would probably start a third world war of debates if Lil Wayne and Eminem ever did a song together. The arguments of who did better would be second only to "Takeover vs. Ether" in terms of how much it would potentially be discussed. Unfortunately it doesn't seem to be in the works, because Lil Wayne revealed that Eminem brushed off his attempt to collaborate.
“I’ve never done a song with Eminem,” Wayne says. “I sent him a song and he ain’t do it. I didn’t like that but it’s all good. People be busy and stuff or a.k.a. just scared to get on a song with me.”
Is Eminem scared to hop on a song with Wayne? If he's not afraid, could this be taken as a sign that he simply does not like Wayne? It's quite possible that he didn't do the song based on his friendship with 50 Cent. In other news, more reports surfaced today that Eminem is in the studio with Dre working on the new album. It seems as if every six months, more stories circulate that they're "hard at work" on new material.
"Hip Hop DX":http://www.hiphopdx.com/index/news/id.6587/title.eminem-scared-to-record-with-lil-wayne