Mozilla has announced Thunderbird will follow the Firefox Extended Support Release (ESR) plan. The current plan is the first Firefox ESR will be based off of the upcoming Firefox 10 release coming at the end of this month. With that release comes a 12-week ‘grace-period’ for continued support of the Firefox 3.6 release which would put the final release on April 24th, 2012. However, Thunderbird has been a bit slower to adapt to new release processes (the first rapid release cycle release was Thunderbird 6). It is uncertain at this time if the first Thunderbird ESR will be based off of Thunderbird 10 or 11 (in which case the end date would be June 5th, 2012). There should be more news about this later this week or next week.
