I seriously doubt Maria would play mixed if she thought there were any chance it would harm her chances at singles.
So if she decides to play, we shouldn't worry.
I think it would be nice if she played with Youzhny, I like him.
But don't other Russians want to play mixed and are also more experienced and actually better than Maria at it?
Also, hadn't she said something about it at a press conference at RG? Something like "nobody asked me to play mixed"?
So I guess it's a possibility.