My theory as to how The Shield will end..

Vic will get killed, in such a random, quick, pointless way by some 14 year old gang-banger wannabee during some gang initiation... you won't see it coming... Vic in his car... thinking his life is finally in order, and at peace, and then BAM!... fade to the 14 year old... shaking, sweaty, nervous, dropping his smoking gun, and running off into the night. The irony would be so thick.. such a vicious, street smart cop, who took on countless powerful criminals, killed by some rookie "next generation" thug, not old enough to even drive.