The goal of this group is generally to identify areas (and work on them!) that GNU Radio can change to improve performance on GPPs. VOLK is basically the bulk of that. I want to highlight that one of the primary outputs of the working group was a desire for data to guide optimization efforts.
If you know of blocks with work that can/should be vectorized, point that out. I'm not sure of the best location to track this, whether it's the redmine issue tracker or a wiki page, as it would hopefully be a revolving door type of list. For now just email the list (or reply to this email would be great).