As the site is about Russian language should it allow Russian tag names (that is cyrillic names)?
The German SE has tags in German, but do cyrillic letters make things different?
It appears that they do. I tried to retag this question by adding 'дискуссия', and the tag disappeared as soon as i hit space. This seems to be a problem. Here's the feature request/bug report to have support for Cyrillic tags added, support it!
Update: SE inc. employee has confirmed that Unicode support for tags is in the works, but is still some time away.
This is now enabled on russian.stackexchange.com and meta.russian.stackexchange.com, however please note that you're the first. This means it is entirely possible that there's one or two bugs hiding in the corners, waiting to pounce.
If you see any issues in the behavior of your tags (whether cyrillic, ascii, or other), please let me know directly.
I like the idea of Russian tags, however IMHO they should be used only where strictly necessary. As an example of proper use, I'd welcome tags
тс-vs-ц. However we should not use Russian words to name general topics, like stress, consonants etc. because this would make it hard for foreigners to use the site. My opinion is that this site should be as non-Russian-speakers-friendly as possible. There are many good Russian-language resources on Russian and very few non-Russian ones.
This doesn't mean that Russian askers are not welcome here, on the contrary. But we should have a clear set of guidelines, and tagging is one of the mechanisms to enforce them.