nope...least not yet. Jericho and his band fozzy has lent many songs as themes for PPV's in TNA, and Jericho in recent interviews has changed his tune as it relates to the quesiton of when he's returning to wrestling. Previously he would say that he is done, the desire wasn't there. Lately he's more open to the idea of returning to the ring sooner rather then later. I'm sure TNA is speaking with him, but Jericho has always maintained that as much as he loves TNA and as much as he can pick apart the WWE for there mistakes, he would still most likely return to the WWE. Also Jericho is not a fan of Vince Russo, which is a major negative for Jericho's chances of ending up in TNA. Anything is still possible though. But as of this momment right now, Jericho is not signed or verbally agreed to go anywhere.
The reason for the rumor is because of the comment he made that Hell Rell mentioned about a 4 sided ring never being able to contain Jericho. Some beleive that was a hint that he would go to TNA, others believe he was just saying he's larger then wrestling as an ego thing. Also keep in mind Jericho loves to fuel the rumor mill. Prior to Christian going to TNA when the rumors were running rampant that someone from WWE was jumping to TNA, Jericho posted the following image attachment on his official web site. This lead to many believing he was the one going to TNA. He took it down a week before Christians debut. So his comment may have been ment to indicate going to TNA, which in turn could be Jericho just playing with the smarks.