Hobie is apparently referring to the 2009 and newer Drive as V2. This is a misnomer though, as the Mirage Drive has undergone continuous design and materials evolution on different components throughout the years. There have been at least 3 different sprockets, 4 drums, 3 pedal cranks, 2 pedals, 3 pedal adjustment assemblies, 2 idler pulleys, 3 cables, 4 Turbofins, etc. etc. These parts have been added independently on a continuous basis, not necessarily related to model year changes.
The V-2 Drive probably got its designation from the current sprockets, the only parts actually marked "V2" -- first introduced in 2009 to distinguish them from their predecessors. Their distinguishing feature is a brass insert and threaded mast -- a significant improvement.
Just as important, a new generation drum was introduced in 2008. It is stronger, less prone to warpage, uses different cables that are easier to adjust, and imposes less wear on the cable swedges. The current version has a Stainless insert molded in for minimizing wear on the pedal adjustment holes.
Essentially, the 2009 (and newer) Drive is a major improvement to the 2007 Drive, with 2008 as a transition year. There have been several improvements since 2009 however (pedal position bungees, pedal pads, splined drumshafts, Drive alignment pin, and others.
If you're looking to upgrade an older drive, these are the two items you would want to focus on (1. sprockets/masts and 2. drums/cables, each available as kits).
There may not be a single part still in production from the original Mirage Drive. Any of these old Drives are now referred to a "Older Drives" in the parts book. The amazing thing is you can upgrade virtually any Mirage Drive to current standards -- even the oldest ones are not obsolete!