http://en.rian.ru/mlitary_news/20120322/172317814.html

The Su-30SM is a twin seater which will augment the fleet of new single seat Su-35S's.

As of today the Russian MoD has on order: 120 Su-34's, 30 Su-30SM's, 48 Su-35S's and 28 MiG-28K's or 226 new airframes.

Russian aircraft industry sees a reviving of its former glory!
Clearly only this 226 airframes makes RuAF the strongest one in Europoe and new airframes will help flight hours go up. Still however i am w8ing first AESA equiped plane to be fielded by Russia.

What advantages do the Su-30SM(besides thrust vectoring)have over the Su-35?

They both have thrust vectoring. The SM is a Russianized Su-30MKI with all the French and Israeli toys removed. A twin seater optimized for bombing. It should be inferior to the Su-35S in the AA role as it will not come with the Irbis radar, but instead will come with an older Bars derivative set. It should be a better bomb truck than the Su-35S, and cheaper too. The Su-35S wont be certified to fire every PGM in the Russian arsenal for a number of years yet while the Su-30MKI has already been certified on basically every kind of ordinance. That's really what's driving the procurement.

Thanks for the info Irkut!

Which version of Bars though Irkut ? as far as I understand it had several revisions.