The new Thundertab has (partially) landed in the nightly builds of Thunderbird. You’ll need to get Lightning installed to see all this and it’s not too pretty yet, but we’re making lots of progress.
But there’s no time to lose! We’re already talking about how to handle tab session restore to keep all your opened mail tabs around for future sessions.
I’ve put up a partial mockup already, but it’s still early. As always please leave comments below!