TallSally:

 I have Comcast and very happy with the service and price, can we add Direct TV (russian and japanese channels) or that's impossible from technical point of view?

It's possible, but you're not really adding it to Comcast.  You are subscribing to DirecTV satellite service in addition to Comcast.  Most TVs will allow you to hook-up multiple receivers at once.  On DirecTV you can just order Russian and Japanese Packages and not the basic service, but to get the most promotional offers (like free installation, free equipment, free HD-DVR, etc.) you might consider subscribing to basic packae + international channels for 1 or 2 years.  It might be cheaper overall.

Check out TV link on the top of the page to see what Russian channels are available from DirecTV.