Forum:Udina vs Anderson?

In most of my playthroughs of ME (and subsequently ME2) I nominate Anderson as the Human council representative which I always feel is the better choice but after playing the ME3 demo, in which Anderson is an Admiral, I read the to articles on both Anderson and Udina and both seem open about the choice until ME: Retribution where suddenly Udina is the Councillor. Having never read the books/comics I would like to know if this is the canon version (if so why give you the choice in ME2 to re-choose whom you want, as the decision not carried over with save-transfer?!)?

Is it ever explained or will it be better explained in ME3?

P.S. Sorry if this is in the wrong place or in the incorrect format.