I have five svchost.exes running, two in SYSTEM, one in LOCAL SERVICE and two in NETWORK SERVICE.
As of right now: Local Service: mem usage: 4,128K
Network Service: 3,924K and 3,328K
SYSTEM: 4,488K and 38,236K.
The last one CANNOT be right, downloading AVG right now. Done a cache dump. No slow-down through normal PC use, only some slowdown in the Stalker: Shadow of Chernobyl menu. This slowdown is what prompted me to check through task manager.