I've heard guys in the pre-game lobby say "oh hey, bob is host".
 
Anybody know how to tell in the lobby who will be the host?

As far as I can tell, you don't.
 
The only way to know if its you, is if you can kick people. Beyond that... nothing I think.

You don't.

" As far as I can tell, you don't.  The only way to know if its you, is if you can kick people. Beyond that... nothing I think. "

They might be talking about party "host" (aka whoever in they're party is leader and needs to back out first if they wanna leave)

EDIT: If you wanna find out game host, pick your class right away when the game loads and hit back/select, everyone but one person should have low connection for a few seconds, the guy who starts at good connection is probably game host

There are ways to tell people. 

usually if someone where doing much better then everyone else there is usually a guess that he might be host just because he isn't getting hit with much lag.  But its really hard to know for sure.

The first person who gets in the game is host, the person with 4 Green bars before everyone is host. The person who ONLY has 4 Green bars. 

What   ricetopher said, the host will be with a full green connection while all the other connections work their way up starting from a poor connection. 
 
If there is a group of six and the lobby is merged with another without the map changing, then someone in that group will be host; if the people play together regularly then normally it will end up being the same person hosting.
 
@kenya24: you can't kick people in a public game.