How about this. Instead of making stupid suggestions like nerfing guard, how about you have some skill and separate the tank from the guarded target. Trust me this works.
On another not... As a healer there is nothing more annoying that a dumb tank that throws up his guard the runs away to go DPS... dude seriously... Like Elrithis said, your job is not to dps but "Control" the enemy that is attacking your guarded target. As a healer, if the tank runs in the fray to dps just to maintain guard the healer has to run in the fray...