I mentioned updating the baseclasses before.
The newest release can be found here:
http://www.microsoft.com/downloads/d...displaylang=en
On 27-4-2009 MS said they would not be updating the directshow baseclass redist dll's, this probably also means that they won't be updating the baseclasses at all. However they could still update them through windows update (redist is no longer required with XP sp2 or newer)
I guess this is a logical step seeing as all the focus is on media foundation.