If slashdot could seperate out say, it's front page logic from its comment logic, then the front page will always be speedy and the comments section be its relative speed.

That's exactly what Slashdot does by serving a static HTML file to anonymous users. No RPC necessary, unless you count the NFS directory shared between all web heads (hidden behind a load balancer) as RPC. It's out of process, so I say it's not.