I doubt any PPC plugin will ever come. The PPC Outllok is not near as robust as the desktop version. I don't think that Pocket Outlook will ever be able to support plug-ins.
You can use third party PIM that are more robust than Pocket Outlook. The two biggest are Pocket Informant and Agenda Fusion. I have used PI for about 2 years and really like it. It carrys over all of my contexts and such to my PPC. I do not use the Add-in so I do not have all of the views and, as such, cannot comment on if they transfer to the PPC.
There are lots of threads about both of these programs here and around the net. Another place to look is at Merlin Mann's 43Folders .