With regards to this thread’s title, if by “linked data” you are referring to the Semantic Web, then microformats do not have anything to do with Linked Data. Linked Data (with capitals) is a very specific entity whereas, linked data (lowercase) can mean just about anything. So, I’m just trying to clearly understand what you are suggesting.
It is important to know that what the Microformats community calls POSH (Plain Old Semantic HTML) is not the same thing as semantic markup which uses RDF classes and properties to model relationships between data. Semantic Web applications are built using a stack of W3C technologies.
http://linkeddata.org/
But I agree that properly semantifying BuddyPress via Linked Data protocols is a great idea!
like Jeff said… i prefer having hyper-efficient semantic than extraneous features… 
“Linked Data” in as much as having RDF documents using FOAF / SIOC.
@DJPaul-
I thought as much but I just wanted to make sure I understood what you are proposing.
So, +1. Or, maybe +2 since @nexia has already indicated his support!
