Sql Server Agent REPL Jobs I know that replication uses Sql Agent jobs to pull subscriptions. Are these jobs supposed to stay in an 'executing' state? (Sql 2008 SP1)
Replication agents run as jobs scheduled under the SQL Server Agent.  They can be scheduled to run continuously or on a recurring schedule.

If the replication has been scheduled to run continuously, then yes, it could be continuously 'executing'.