I like to call it Urban Arcana (because that's its name), and I'm currently running two games: one online, one offline.  So far in the offline game, two PCs are earth-born humans, one PC is an earth-born tiefling, and two PCs are former denizens of Aber-Toril--one a goblin ninja (fast hero), and the other a sun elven bard (charismatic hero).  In the online game, at least one player plans to replace his PC with a shadowkind (drow) once the party level gets high enough to allow races with LA.
It's a blast having former fantasy PCs in a modern setting.  The goblin has thus far discovered "plastic" (I can buy without having money?!), tequila, refrigerators, automatic sliding doors, coffee, and guns.