So far there is not much information to go by, aside from the fact that it will not be like AdSense (which Google rolled out on Orkut not to long ago), and it will be used exclusively by Orkut (and no other site).
While it may seem odd for Google to roll out a premium service for Orkut (after all, they just purchased Double Click earlier this year), Google may be trying to find a way to make Orkut profitable (as hosting all of those images, apps and keeping every bodies scrapbook alive can be quite expensive).
My theory is that Google may be launching some sort of Orkut classifieds (in order to target local markets), although we will have to wait until next year when the service goes live to the public.
Note: I wonder whether or not Google will roll these out on Orkut profiles? (since they probably receive more traffic compared to Orkut forums).