This new musical comes with as many bet-hedging safety catches as they could muster. After his blockbuster The Producers, you cant blame Mel Brooks for breeding another movie-to-stage cash cow (if this one catches fire too, look for a musicalized Blazing Saddles to complete the trilogy); nor for launching it in the city that birthed Hairspray before it conquered Broadway and returned full-circle to the screen this summer. And to draw the gay audienceif thats not redundanttheyve cast Roger Bart (who swanned memorably through Producers as Carmen Ghia) as Dr. Frederick Frankenstein (thats Frahn-ken-steen) and camp diva Megan Will & Grace Mullally in the Madeline Kahn role of Elizabeth. Its just the sort of calculatedly cant-fail project that makes critics sharpen their knives, twirl their mustaches, and say Oh, yes, it can. MWAH-HA-HA-HAAAA!!! [Gothic organ chord].