Would be interested to see if he did get a job back at RTE, I would bet he would be back there on a higher wage (as an even higher profile person). If he didnt get that one back he would probably get a job at TV3 so its not really the noble gesture that some are making out.
He has been very clever. Constantly attacked FF as an impartial observer, which has added credibility to his arguements. Then, either because he was always a FG supporter and didnt disclose it, or he sees an opportunity to invest on the wave of disgust at FF by getting into politics (and using his already known image in public to get him in).
I dont know exactly his motivations for doing this, I can only speculate, but I would not think they are for simply doing his bit for the country (I openly admit to being a cynic).
That said, FF havent exactly raised the bar very high for any party to improve on so it should be a walk in the park, if FG dont get into power (even with labour) they should both give up . . .