That's right, plus you can nowadays put more effective weapons, countermeasures and sensors fairly easy on the new variants of the Mi-8/17 and other transports. However although the concept of the Hind might be obsolete for Russia's armed forces, it won't be for many others. It's still in production, and I think it will live on for long beyond 2015 elsewhere.
Actually, I can't imagine all of them Hinds being gone from Russian armed forces by 2015 either. At least not solely due to the Mi-28N.
I can see some Hinds being retained by the Russians beyond 2015, for at least CSAR and COIN/anti-terrorism, maybe as a new variant or upgrade. It's such a waste to relinquish such a platform, just because the attack mission will no longer see the need for troops to be carried.