The command Get-SPProduct in snap-in Microsoft.SharePoint.Powershell is defective. For 2010 the ProductName is always "Microsoft SharePoint Server 2010". The problem is that this command is supposed to query the Product not the Family of the product.
So the expected result of this command should be "Microsoft SharePoint Server 2010 Enterprise" or "Microsoft SharePoint Server 2010 Standard" or even "Microsoft SharePoint Server 2010 Evaluation".
Now the only way to query this Product information for licensing is: Central Administration > Convert License Type. Only there the current license can be seen like "SharePoint Server with Enterprise Client Access License".
I am looking for a Powershell script that can retrieve this important information in a reliable way. Furthermore it would be nice if the bug in Get-SPProduct would be fixed in future SharePoint products.