VMware-PowerCLI script

Hello!

I created this VMware-PowerCLI script:

Connect-VIServer -Server vcenter.local -Protocol https -User 'mmarnauza' -Password 'pass'

$vm = Get-VM -Name mm.Workstation8

Shutdown-VMGuest -VM $vm -Confirm:$false

echo "SHUTWOWN $vm IN PROGRESS Sleep 10"

Start-Sleep -Seconds 10

It connects to vCenter and does guest shutdown of mm.Workstation8 virtual machine.

At the end I want to create script that's:

1) lists all the VMs in vCenter

2) shuts down all the VMs except vcenter

I want to do script in a way that if I add new VMs I do not modify the script! Anyone can help me with this since I am not very good with scripting