Here is a list of WordPress plugins developers that I follow (in alphabetical order). Most plugins created by these guys are ahead of its time so some of them end up getting merged into the core WordPress code. Being a WordPress plugin developer myself, these guys are great resources for idea bouncing and coaching. I highly recommend following these guys if you are a WordPress plugin developer or enthusiast.
Andrew Rickmann
Alex (Viper007Bond)
Alex King
Donncha O Caoimh
John Kolbert
Joose de Valk
Lester Chan
Mark Jaquith
Ozh
Ronald Huereca