The Su-37 first flew in 1996, and it has impressed many Russian top brass. Also, the Sukhoi company President has a personal relationship with the President of the Russian Federation, Vladimir Putin. The two share a past together as friends, and Putin is said to favor the Sukhoi company.
As a result of this, new and capable Sukhoi fighters will have a slight advantage over their MiG- Counterparts. The Su-37 has been dubbed "Terminator" by the Sukhoi Bureau, and the Russian Air Force has been quoted as saying "We will be very interested in acquiring some of these plans." Unfortunately with the current budget problems, no serious amount of the Su-37 will be purchased until 2002, or as late as 2005. But soon the skies over Moscow will be dominated by the super agile Su-37.
Hope that helps. = )