How do you create an emtpy pool using powershell?

I dont think you can create your pools with invalid or blank entries; but you can create a vip without a pool... try this.

$vipDefs = new-object "iControl.CommonVirtualServerDefinition[]" 1
$vipDefs[0] = new-object "iControl.CommonVirtualServerDefinition"
$vipDefs[0].address = "0.0.0.0";
$vipDefs[0].name = $vipName
$vipDefs[0].port = 0;
$vipDefs[0].protocol = [iControl.CommonProtocolType]::PROTOCOL_ANY;
$wildmask = @("0.0.0.0")
$resources = new-object "iControl.LocalLBVirtualServerVirtualServerResource[]" 1
$resources[0] = new-object "iControl.LocalLBVirtualServerVirtualServerResource"
$resources[0].default_pool_name = ""
$resources[0].type = [iControl.LocalLBVirtualServerVirtualServerType]::RESOURCE_TYPE_IP_FORWARDING
$profiles = new-object "iControl.LocalLBVirtualServerVirtualServerProfile[][]" 1
$iControl.LocalLBVirtualServer.create($vipDefs, $wildmask, $resources, $profiles)