Back in the day Kamov apparently made some rather derisive comments regarding the (in)ability of hiding rotor blades from radar. They viewed the LO features of the Commanche as of relatively limited value.

On page 13 of this article you will find the very rare (probably only) concept art showing a Kamov successor helicopter with some low observability features (eg. internal weapons stowage):
http://www.take-off.ru/pdf/12_2009.pdf

By the way, two of the best threads for this kind of thing are:
http://www.secretprojects.co.uk/forum/index.php/topic,3125.0.html
http://www.secretprojects.co.uk/forum/index.php/topic,2766.0.html

You have to register to see the pictures. Anyway, I always thought an Mi-35 or Mi-40 would've been great to test fly in Arma/Arma II... instead ARMAIII is giving us an Mi-28 with a three barrelled gun (IMHO, Russian weapons tend to jump from twin barreld gast-guns to quad barrelled guns - I don't think they've ever deployed a three barelled weapon)?? Oh well, more work for modders.