There are dialects in every language. In fact, Russian, Slovene, Czech, Sorbian, Ukranian, Bulgarian, Belorussian, Polish, etc all ultimately began as dialects of Proto-Slavonic in the same way that French, Spanish, Italian, Portuguese, Catalan, etc began as dialects of Latin.

The idea that "dialects can't happen to Russian" is completely ridiculous and spawns from the widespread misconception that languages are static cultural artifacts. They're not. They're living, breathing, changing.

Keep in mind that Belorussian and Ukranian are considered by some linguists to technically be dialects of Russian.

There also exists, of course, the blatnoy dialect, and I'm sure there are differences in speech between the socio-economic classes as well as, however minute, differences between regions in areas such as word choice, consonant and vowel changes, etc.

Although language change is inevitable, it remains to be seen whether languages will progress more or less uniformly in their change given the "MTV effect" which I think was mentioned.