Hey, so Minecraft: Pocket Edition has recently been updated to allow for external servers and there is a bukkit type application that allows users to host their own servers as well as several paid hosting services.

while all parties involved are still at alpha development stages, they'll only become more and more popular, and the need to distinguish PE servers from PC servers will become more and more apparent.

i have 1 running here:

http://www.gametracker.com/server_info/70.71.26.166:19132/

and i know at least one other person has submitted their server to this site for tracking.

cheers, -u.