Well I have seen many versions of Shakespeare done with all male casts and one version with an all female cast. And they both worked very well. Lady Ice you are wrong that it stretches imagination to have a man play a coy female, I have seen it done and seen it done very well. In fact I've never seen a male actor play a female in a "butch" way. Probably because they are so focused on being female that they don't want to risk coming across as anything but. More impressively was watching the all female cast and forgetting at times that some of the performers were women. I even developed a little crush on the girl who played Don Pedro (it was a production of Much Ado About Nothing done at The Globe theatre in London UK).
Those of you who think it'd be funny to watch, I will say that at first it is odd, it takes some getting used to, but eventually (and especially if the actors aren't playing the all the same gender thing for laughs, but treating their roles with the seriousness any role deserves) you find yourself actually forgetting about the gender thing. A perfect example of this was an all male production of Twelfth Night. At the end, after all has been resolved and the couples paired off, Orsino went to kiss his bride, except he mistakenly goes to kiss Sebastian thinking it's Viola. I remember thinking at the moment, "Ah no! That's a boy!" But of course Viola was also being played by a boy. I was so in the play that I'd totally forgotten.
It can be done, I've seen it done, and it works. My only gripe with it, is that people tend to do all male Shakespeare more than all female, and with so few female roles in Shakespeare to begin with, us actresses kind of need the parts. So I resent all male productions simply because it takes roles away from women that are sorely needed.