Everything you can do in the VMM Beta 2 Administrator Console you can do on the command line. Our PM puts it best, "Our API is the customer's API".
For example, a beta VMM user recently asked "How can I specify which bus/lun I want to assign myHD to when I create a new vm? It seems that New-VM isn’t happy if you don’t pass it a –virutalharddisk parameter so I can’t seem to create the VM first and then use Add-VirtualHardDisk."
You can do this in a job group, here’s an example that shows creating a vm in a job group that adds a VHD to IDE 1,0 and adds a NIC:
$job = [Guid]::NewGuid().ToString()
New-VirtualNetworkAdapter -VMMServer localhost -JobGroup $job -EthernetAddressType Dynamic
Add-VirtualHardDisk -JobGroup $job -Bus 1 -Lun 0 -VirtualHardDisk $VirtualHardDisk -IDE
New-VM -VMMServer localhost -Name $name -VMHost $VMHost -Path $path -HardwareProfile $HardwareProfile -JobGroup $job -runasynchronously
You can use this to do new-vm related cmndlets before calling the new-vm itself (such as adding VHDs or adding a NIC in this example)