Someone I know who is close friends with the Manning family says Peyton is definitely interested in coming to the Texans. Manning will be released by the Colts early next month and will be a free agent. The person who knows the Mannings says Peyton wants to play on a team that has a chance of going to a Super Bowl, and the Texans fit that description.
Another big plus is that the Texans are in the same division as the Colts. Manning not only knows the division, but I'm told the relationship between he and Colts owner Jim Irsay now is strictly business. And don't underplay the competitiveness between Peyton and Eli -- it does matter that Eli has two Super Bowl rings to Peyton's one.
This is one that won't be played out publicly; we won't be hearing anything from Manning or the Texans unless something does happen.
A big factor is Manning's arm strength and right now he's still not back to what he was, but it's still early. And then there's Matt Schaub to factor in as well.
All that aside, be it a long shot or reality, I know for a fact that Manning does have a definite interest in the Texans.