It's just a waste of time and money. Either they throw together tag teams, which is done all too often, or bring in X division tag teams, which is a waste of money.
What they should do is just create a mid-card championship like a TV title. Then they could have X-Division guys and Heavyweight guys fighting for it. It would give those guys something to do, and also it would help to blur the line between the X and Heavy Divisions. If X and Heavy guys are winning this TV title from each other it would make the divisions seem more equal.
On a side note, I think Joe as X champ, makes the title look almost equal to the World title. AJ of course does that for people familiar with his World Title runs, but I think putting it on a big guy like Joe does more for the casual viewer, if TNA has any of those.