Absolutely Essential Rated 5 out of 5 stars
"For the future we are planning to integrate Lightning fully into the upcoming Thunderbird 3 release"
And the World will be a better place because of that. :)
I've used Lightning for just about the same amount of time that it's been available. I've loved it since day one and I'll continue to because it will only get better.
Thanks to all who have contributed to the development and maintenance of Lightning.
--You guys rock!!