I've been complaining for ages about Microsoft's lack of support for Print Services on Server 2008 R2 via their SCOM print management pack.
Finally I'd had enough of it and made some time to sit down with Rob to take a look.
The end result is that Rob has produced a simple management pack that runs a discovery with the correct WMI query to look for 'Print and Document Services' rather than 'Print Services' and populate the group used by the Microsoft MP so that the rest of the Microsoft MP will discover the printers on the R2 server and collect the performance data.
You can find the MP at the bottom of Robs blog post.
This is NOT a supported method; this pack has been created as a personal temporary fix so use at your own discretion.
Use at 'your own risk' and AS-IS with no warranties. As always use a test environment.