Bunnyhopping shouldn't be a problem, since running and jumping speed are the same.
http://www.splashdamage.com/forums/showpost.php?p=215412&postcount=1037
In other games I've played, jumping normally was the same speed as running, but bunnyhopping was faster because crouching makes the falling arc longer, so you pick up speed.
I don't think that Brink has Bhopping, but having sprint and jump be the same speed doesn't stop Bhopping, especially when many people do it to dodge bullets, not necessarily to move faster.