Michel, final point (definitely!)
Phone longevity is reducing. Used to be 3 years, now down to 1 year for some networks. And experts are saying that unsubsidized Android smartphones will be less than $100 by the end of 2012. IMHO the telephone providers expect consumers will prefer to replace rather than messing with OS, especially with the rapid hardware evolution expected between now and 2015. If this is true then maybe it's best to choose on price in 2011 in the expectation that you'll want to replace in 12-18 months anyway.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1