TempDB -no. It's recreated every time the service starts.
Model - not unless you've made changes to it.
MSDB - yes. It's where your job definitions and history, backup histories, SSIS/DTS packages and similar are kept.
Take sQL backups of the databases and don't depend on ghost. Unless it's aware of SQL, the backups of the system databases that ghost takes could be unusable
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability