The Zumo 660 will be released 1st quarter of 2009 (Jan-Mar). Looks like they are now providing motorcycles with the same features found only on car sat navs until now - lane assist etc. I for one will be very interested in this gadget which will be the best bike sat nav on the market at this time.
https://buy.garmin.com/shop/shop.do?cID=135&pID=15000#featureTab
https://buy.garmin.com/shop/shop.do?cID=135&pID=15000#featureTab