Perusing the web I've read that the M80v2 has improved
cross overs and upgraded binding posts. What physical
differences distinguish the M80v2 from the M80ti?

Depending on the age of the M80ti you're comparing the v2 to, the tweeter / mid configuration changed, the corners were angled from a rounded corner, and the binding posts were upgraded.

When did the V2's come out?

The V2 *designation* came out quite recently, with the last 3-4 months I think. Other than what it says on the plate, though, it seems the design and fittings changes took place gradually over a number of years.

In the case of the M80, it sounds like the speaker arrangement was changed first (from TMTMWW to TTMMWW, years ago), then the crossover, then the binding posts, but don't take that as gospel truth.

You know, I wondered why my new M80v2's came in boxes that say "ti" on them. I guess they needed to use up the old boxes!