http://dottech.org/tech-news/73932/bye-bye-thunderbird/ Looks like they're also moving to a cloud based / webapp store... I don't like not having all my mail on my HDD as well as in the sky. Mozilla's new app store: https://marketplace.mozilla.org/en-US/login
I do not like "Clouds" at all.... I would NEVER let others, control my Data.... Prescription for Disaster, and an invitation for .Gov Snooping.... ..... YMMV....