Personally, I think they should hold off on this until the next level-cap increase (let's say lvl 60), where they could revamp EV/KP/EC, but leave the current ops at 55, since people will be bored with them by that point. Then the expac after that (level 65) could bring back the current ops. That would set up a rotation between the sets of ops so that they don't get as stale (of course new ops would still need to be released).
I think this is a terrible idea for one reason: there would be very little content for people to do post-50/51 through 55 (or the next level cap -5 ) if the Classic and current Level 55 Ops were constantly being re-engineered to be higher and higher levels.
Right now, class story nominally carries a character from 1-50. Ilum and Makeb could
carry a character through from 51-55, but let's face it--with a single track, those can get kind of stale. They have the SM and HM 50 Flashpoints, but that and possibly Dailies would be it under this scheme.
I don't think the OP's idea is a bad one, although it would effectively be a NiM+ difficulty. But I'd wait and see how 2.4 and the two new 55 Operations there makes things.