Just wondering if this game will use the dreaded matchmaking system for joining games in MP? Or if there will be a custom game feature where the game creator can choose certain aspects like, map, missions, classes, weapons?

Thanks.

Oh and will there be a beta and if so will PS+ subs get it?

For the beta, read the FAQ: http://www.gamesas.com/index.php?/topic/1113952-brink-faq/
For the matchmaking, read the FAQ: http://www.gamesas.com/index.php?/topic/1113952-brink-faq/

Nothing has been released about custom games for consoles.