Set's all Web and Worker roles in a subscription to a single instance.

Set-AzureMinimumInstanceCount.ps1

$deployments = Get-AzureService |
  Select-Object ServiceName |
	Get-AzureDeployment
$instances = $deployments |
	Select-Object ServiceName,Slot -ExpandProperty RoleInstanceList
$instances |
	Select-Object ServiceName,Slot,RoleName |
	Group-Object RoleName,ServiceName,Slot -NoElement |
	Where-Object {$_.Count -gt 1} |
	Select-Object Count,@{Name="RoleName"; Expression={$_.Name.Split(',')[0].Trim()}},@{Name="ServiceName";Expression={$_.Name.Split(',')[1].Trim()}},@{Name="Slot";Expression={$_.Name.Split(',')[2].Trim()}} |
	Set-AzureRole -Count 1