RIM issued a press release today (BlackBerry - Press Releases) where they officially announced OS 6. The interesting part of the press release is in the section "Compatibility with Existing BlackBerry Smartphones." While they do not explicitly mention the Storm 2, they do say OS 6 will be available for devices currently on the market.
Here is the relevant part of that section:
BlackBerry 6 will debut on the new BlackBerry® Torch™ smartphone (announced today) available from AT&T on August 12 and it is also designed to run on select BlackBerry smartphones already in market. Subject to carrier certifications in the months ahead, the new OS is expected to be available for the BlackBerry® Bold™ 9700, BlackBerry® Bold™ 9650 and BlackBerry® Pearl™ 3G, as well as future BlackBerry smartphones