The W650 has come and gone in the States, no longer sold here since 2000. It was ahead of its time, slightly preceding the Bonneville which resurrected that style in a way the W couldn't, probably because the numbers Kawasaki expects to sell in order to consider it a viable model are considerably different from what the smaller Triumph company would expect.
The Ws still have a cult following of their own, and used ones can be found pretty readily on ebay or craigslist. I personally think it's a great bike. Unfortunately the new W800 probably won't be offered here either.
[Edit] At this moment there are two on cycletrader.com, one with 9,800 miles for $6,500 and the other with 34,000 miles for $4,000. Better deals can be found but that should give you some idea what to expect.