I can confirm that when you throw a snowball at a rogue/druid as opposite faction he/she will go out of stealth and in combat.
Good for if a rogue/druid tries to run, just keep on throwing snowballs
Snowballs are cheap, easy to get and can be thrown instantly from a range.
Basically rogues their worst nightmare right now are.. snowballs, i hope Blizzard fixes this soon