In ESXi 5.0 , "esxupdate" command changed to "esxcli software vib list" .
In PowerCLI, invoke Get-VMHostPath, command successfully , but result is empty.
Get-ESXCli doesn't work quite like get-vmhostpatch.
A dirty way to get this accomplished is to ue the update manager cmdlet get-compliance , after installing UM PowerCLI and creating/attaching/scanning/remediating a baseline.
Thanks for reporting this issue, I have raised a bug for this.