Colin has two other teams. The LMS one is due to put a new car on the track next year and will surely need extra leadership time, and the DTM one is ticking over nicely.
It's very complicated - the team is run by Kolles, the top staff are contracted to him personally (many of them work in the aforementioned other teams when F1 doesn't have a race) but Colin doesn't own the team. Some rich Spaniards who haven't been putting in much money own the team.
This sounds to me like a falling-out, especially given that Narain Karthikeyan (someone who Colin has worked with at Jordan as well as Hispania, and with whom, apart from a falling-out mid-2005, has always been on good terms) has gone. Maybe he was outbid, but Red Bull surely can't be looking to buy a third team. TATA have changed teams a lot because they're loyal to Narain - they followed him from Jordan racer to Williams tester, went to Ferrari when it looked like Narain wouldn't come back to F1, then went to Hispania when Narain somehow got back onto the grid.
I have a horrible feeling that a sale may be the only thing that will save the team, that Colin's worked that out and has decided to bail to focus his attention more efficiently on teams that are salvageable.