Although you hear rumblings of such things from time to time, this is the first time I've seen anyone write it down. From the Tennessee Journal:
It has long been speculated that if the Democrats maintain control of the House in November, [Rep. Gary] Odom will challenge Naifeh for the speaker’s position. But distribution of the newspaper article, which Odom jokingly described as Frist’s “first mail piece,” likely had nothing directly to do with any such aspirations.
Whether he has designs on the speaker’s job or not, Odom clearly wants to play a lead role in defending his party’s majority. He will be somewhat less free to get out to other districts than he had hoped because he faces a challenge of his own. Republican Timothy Lee, a paramedic paramedic, stands little chance against Odom but will force him to campaign some in his own district.
Naifeh too has an opponent, Covington Republican Rory Bricco, but is expected to win reelection handily.