cclark, I would NOT count on a brand new (less than a year or two old) road being on the 2009 or even the 2010 Navi DVDs. They just don't work like that. In a rare case, you might find a very recent road on there, but not likely.
There's a whole subdivision near me that's been around for 10 years - NONE of it is on my DVD! Nor is it on Mapquest. These things are SEVERAL YEARS behind reality with regard to road changes. All of them are, as it's just too difficult to catch up & keep up, I guess. It's one of the frustrating things about GPS - the maps are expensive and updates are STILL out-of-date.

Edwin, the .a .b .c etc, are just minor updates to the 6.62 (for instance) release. The later in the alphabet, the newer THAT release. Of course, the higher NUMBER is a more recent release. Thus 6.62.a is newer than 6.56c (and way newer than 6.11c).
The Accord and Pilot use a different numbering (and coloring) scheme altogether. It's orange or white, as I remember. Ours (and the CRVs' I think) are teal or turquoise.

Steve

STOP terrorism - Drive a HYBRID

Vehicles:
350 miles a week ------------ 2006 HCH II, Magnetic Pearl, w/NAVI (born on May 25, 2006)
350 miles a month ---------- 2003 Mazda Tribute ES-V6
350 miles a year (for now) - 1986 Mercedes 560SL