Let me tell you why you're not only screwed when you want to run Poulsbo systems on Linux:
Intel does not only have bad support for Linux, it even excludes any email support, even for Windows for the Intel Poulsbo Chipset: "Intel does not support this product via email."
see http://supportmail.intel.com/scripts-emf/defaultlanding.aspx?productid=3180&srchidstr=39,1101,3180 and it seems does no longer supply driver downloads: http://downloadcenter.intel.com/NotFound.aspx?ProductID=3180&lang=eng. Ok, the last is wrong: http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&ProductID=3001&DwnldID=17992&strOSs=45&OSFullName=Windows%20XP%20Home%20Edition*&lang=eng
Now what other support options are there from Intel? Contacting your manufacturer often does not prove helpful either. MSI's support even seem aware that the Poulsbo chipset is supposed to have active video decoding acceleration. They inform that the Poulsbo chipset is not a high end chipset and you shall just disable video decoding acceleration in case it crashes your Windows system.
Considering the overal bad support for the Poulsbo chipset I can not recommend using it: No good Linux driver, no good Windows driver, DXVA announced but not working(not even in Windows), no email support, no Windows driver downloads, etc.
So I think: don't buy Poulsbo systems.
Intel advertises features it can't deliver and doesn't support the chipset. And it's really sad to bring out a chipset that won't be supported well until maybe 2010.