I agree about the multiculturalism. I've heard that Lavie Tidhar does a lot of this, bringing in Hebrew mythology. I've had Snake Agent (the Liz Williams book) suggested to me before, and I plan to getting around it. American Gods had some occasional variety in it, too.
More... types of urban fantasy would be nice, too. There's a lot of detectives, and the Magic Council, which pops up
everywhere, even in the Potters, is really starting to irritate me. How about something different, like an undersea investigator or an Indiana Jones archeologist? Strain the genre.
I have a Sidhe spy book brewing, though I don't know enough of the mythology to be able to write it yet. To my amusement, Simon Green got to the spies first, with The Man With the Golden Torc.
Oh, and technomancy. Hell
yes. Magitech! Like WebMage, or the Mage the Ascension RPG. With some geeks in a world like that, some video game references could pop up.
Other countries, other cities... I love threads like this.