As Marc said here, we have enabled support for Cyrillic tags on this site.
This means you should now go and create some tags in Russian. :) Propose some tag wikis and excerpts as well.
You are the first site that's getting this feature, so there may be some bugs lurking around. If you run into any issues either with the Cyrillic tags or with the plain old English tags, please let us know right away. You can post any issues you find in this thread.
Other than that, enjoy!