The real world mayor, Mike Bloomberg, must hold that position in Toobworld as well. He's made appearances as such on '30 Rock' and 'Law & Order' and "A Muppets Christmas: Letter To Santa". (Which makes me wonder - has he been co-opted by the Scheinhart Wig Company?)
So off 'Castle' goes, entertaining as it is. But at least I'm going to have it set up shop in the TV dimension of 'The West Wing', sharing space with 'Mr. Sterling', 'Smallville', the "re-imagined" 'Battlestar Galactica'.... Not too shabby for company there!
But I'm sure that the sci-fi (Please - NOT SiFy!) conventions must apply when it comes to alternate dimensions - there would still be an author named Richard Castle and a Detective Kate Beckett in the main Toobworld. Only they banter with Mayor Blloomberg when at charity functions.
I don't know what the future holds for either show, but now I'm hoping there WON'T ever be a crossover between 'Castle' and 'The Unusuals'. I don't want to lose the 2nd Squad to a different dimension as well.....BCnU!