16, but have most on my 'to do' list - i'm surprised at who isn't on the list to be honest - someone mentioned Moorcock, - William Gibson, Philip K Dick anyone? (unless they're defining fantasy as 'has magic and / or swords and stuff in it).
It looks like they're excluding authors who only write sci-fi, though they are allowing urban fantasy.
(Come to think of it, do magical realist authors belong on lists like this? It's kind of a shame to see Jorge Luis Borges left out.)
ETA: Also, I don't recall seeing Harry Turtledove on there. He's best-known for sci-fi, but he's done more fantasy than, say, Richard K. Morgan has.