I think that you fundamentally under-estimate the significance of inertial thinking in Russian military and political circles, as well as the lobbying power of Russian defense industries. We will see a fairly massive (relatively speaking) induction of new munitions in the second half of this decade, along side the new PAK-FAs, and some of those munitions will trickle down to the older units.
I don't know if the R-77 is in service or not, I would not be surprised to hear that it actually is "in service" (i.e. passed state trials/experimental exploitation) but numbers are very low. The Russian air force does use the R-77 in practice, just very rarely. MiG-29s and MiG-31s will not be retired in the forseeable future. Quite the opposite. The MiG-31 fleet will continue to be upgraded, and a MiG-41 is in the works to replace it. Additional MiG-29SMTs have been contracted, and MiG-35s are in the works as well (which is just an upgraded MiG-29). That having been said, total fleet size will go down. The Tu-22M, with upgrades, can be a viable platform for some of the same missions that the US uses B-1s and B-52s for. That having been said the upgrades are still in the works, and it's not clear when we will see them in service. The same goes for the Tu-95 fleet. Non-upgraded Su-27 units are relatively few already, and their numbers will continue to shrink as Su-35S and Su-30SM are delivered. They will probably be gone by the end of this decade, if not sooner. The Su-24 unfortunately cannot be retired overnight. Right now they fill a role that very few other Russian aircraft can fill. They are still a go-to strike asset for much of the Russian air force. Retiring them immediately would create a huge gap. Deliveries of Su-34s and Su-30SMs can not be realistically accelerated. They're already going as fast as production facilities and finances allow. The Su-25 upgrade is proceeding just like you suggest, under the Su-25SM program.
Ironically a contract for MiG-29SMTs has just been signed. It was talked about earlier, now it's official.
bmpd -
And the Il-112V has officially been put back into development. It seems that this Ukrainian mess has given the Ilyushin project the edge it needed over Aviakor's An-140T project.
bmpd -
Now my
opinion is this: the Russian air force should retire the entire MiG-29 fleet, and MiG-31 fleet within the next decade. They should instead increase total procurement numbers for the PAK-FA (I know it won't be 1 for 1 replacement) and the Su-34. The upgraded Su-27SM should either be brought up to the standard of the Su-35S or retired also, over the next 15 years. The Su-25 should be upgraded and remain in service, probably with an enlarged fleet size (production has already been started in Ulan-Ude) but with a bigger focus on integrating and making use of PGMs. The strategic bomber fleet should proceed as is, but the PAK-DA should serve as a replacement for the Tu-22M as well as the 95s and 160s.
