He did, yes. Joss and some of his "regulars" (writers and cast both) have been doing Shakespeare readings at his house for over a decade prior to deciding to film this adaptation.
That's cool. I totally love it when Shakespeare's works are filmed and put in a modern setting, but the dialogue is kept intact (for instance, Romeo + Juliet
set in present day California, Hamlet
in New York City, and - assuming the sumbitch ever makes it out of development hell - Patrick Stewart and Ian McKellen's The Merchant of Vegas