Update: Tom Laciano, Program Manager with Office Communications Group, notes that 3PIP stands for "3rd Party IP Phone" (source). More details: http://technet.microsoft.com/en-us/lync/gg278176.aspx
I've been noticing some rumblings of a possible new interoperabiilty certification called "3PIP" for Microsoft Lync. Matteo Nemeth, of Polycom, noted in a LinkIn conversation that the Polycom SoundPoint IP endpoints will be certified as "3PIP interoperability certification" with the new 4.1 firmware.
Also 3PIP documents were noted on presenter Kirk Gregersons PC while he was demonstrating the Lync Customer and Partner Experience snap in for Lync at WPC 2011. (a screenshot of video shown below)
This new certification seems to be aimed at vendors bringing their existing SIP endpoints to a Lync interoperable state.
Currently snom is the only vendor that has accomplished this by bringing their snom 300 and 821 models into the Microsoft Compatible Devices program. (checkout my videos of snom units working with Lync: snom 3xx on Lync Video snom m9 Dect Video ) Perhaps the "3PIP" program will be a formalization of the "other compatibile IP phones" program as shown below?
Whatever this is it means more endpoint choice for Microsoft Lync 2010. In my opinion this should be a good thing.
WPC Presentation (minute 20 second 30)
Some Related Lync Articles: