there is no requirement for new devices to install the newest version.
No, but only the really low-end Android phones are coming out with 2.x anymore and that number is going to dwindle quickly over the next year. And ICS is not as crucial as some people make it out to be since 2.x is a decent platform already and a lot of features have been backported.
The international versions of the S2 and the Note have already been updated to ICS, as have many of the carrier versions (the AT&T Note and Epic 4G Touch, at least).
No, but only the really low-end Android phones are coming out with 2.x anymore and that number is going to dwindle quickly over the next year. And ICS is not as crucial as some people make it out to be since 2.x is a decent platform already and a lot of features have been backported.