With rumours flying around about a 25mp+ 5DMkIII likely to see our stores next year, how many of the current lineup of Canon lenses have the resolving power to utilise such a large sensor?
It's hard to know, because the way lenses are measured (at least at review sites) they use current generation Canons that would not sample the lens at that resolution in FF. For the central APS-C part you can compare to, say, 7D pixel densities (which are much higher than the current FF lineup). For the region in FF outside APS-C I don't know how you would know (unless the current lenses are already oversampled).
Honestly I see this move to big sensors as an excuse for Canon to update their lenses and bully consumers into update their current equipment if they want to utilise a new FF system with proper AF. /2cents.
I see nothing wrong with that... if you really want/need the higher resolution you're welcome to, but it's not like they're forcing you. The lenses you have wont get worse.