Does a frosted glass cause any significant dilution of the beer it holds? I've always been a fan of "the colder the better".  I enjoy using a glass that has been placed in the freezer.  

Obviously, in this scenario, there's frozen condensation on it, but is this enough to dilute the beer such that I'm destroying the flavor by doing so?
I would say that the condensate amounts to no more than 1ml for a 500ml glass, which is a 0.2% dilution. 

No to be too coarse, but I imagine most people dilute the beer more after taking a sip! 

Comparatively, I think the excessively cold temperature will contribute more to destroying the flavor than a small amount of condensate from the glass. 

So, if you enjoy the beer in a frozen glass, then keep at it.