I've done it and would do it again. I've even done it when it seemed gratuitous and didn't mind too much.
However, I did see a production of Cabaret where at the end of the show the MC was stripped naked and thrown into a coffin--it seemed completely over the top and just sort of ruined the show for me.
Yes, we do need a third vampire musical.--Little Sally, Gypsy of the Year 2005.