Good idea. They already do it.
* _The Design and Implementation of the 4.4BSD Operating System_, McKusick et al., p. 29-30.
What SuperFetch does is collect statistics about files hit by processes when they start up, so it can proactively cache bits of those files, to the point that it can cache files read by processes before those processes are ever started, assuming they are either commonly started or started on a schedule.