Some sassenbergers at Driphter.com posted some images and video of the upcoming 9780 running RIM OS6 on GSM networks. They're reporting that the new OS is quite smooth with an updated browser and better UI and it's quite exciting for all those involved.
RIM is an odd duck. Millions of business folks have to carry them so they can't really change the entire device or OS or else Fortune 500 companies will have to run “Your new Smartphone” training classes at massive cost. Therefore, the changes are pretty darn subtle and, except for speed, probably won't effect you or your loved ones.