This is exactly the OPPOSITE of what I want. I consider myself a reasonably high-volume email recipient (>400 actionable emails a day on average).
The problem with "email as todo", which is a habit I had to work very hard to train myself out of, is that it turns your inbox into a to-do list that others can put things on.
This becomes the WORST to-do list ever.
With credit to Amy Hoy (Freckle, 30x500, etc): I believe that the problem is that every email that comes into your inbox is painful because it is associated with an unknown amount of work, and you don't know the amount of work until you open and read it.
Amy's newest product, Charm, is a help desk tool built to solve THAT problem - fundamentally decoupling the processing of email from the work that those emails contain.
My workflow right now includes:
1) first line of defense assistant does triage, cleaning out things that I don't ever need to see and either need deleting, or don't need my input. This includes anything from FAQ to scheduling meetings, etc. 2) second line of defense is answering emails that only need an answer - usually nothing more than a sentence or two. 3) everything else that's left in my inbox requires work. turning emails that do need my attention into todo's means that I can work from a to-do list, or ideally the current day's to-do list with items prioritized onto it with the help of an assistant.
I'm pretty sure that @sivers has a similar workflow that I've read about here on HN, he may be able to comment more.
This makes email 10000000x less painful, and makes my to-do list less like playing whack-a-mole. End of story: it's easier to get more work done. Email is working for me instead of against me. That is email nirvana, or as close as I'm willing to accept today :)
Of course - the problem with this workflow is that it requires another human. I don't know if that's avoidable. Truthfully, the people who I've hired who work with my inbox I trust deeply. My inbox is a strange dichotomy of a place that is private, but that anybody can send something into. He needs a lot of context for making smart calls, and for me, I need to trust him to make those calls.
Email clients need work - a lot of work - but this is more than renaming the statuses of an email and showing me who I've emailed most recently with.
Take the work out of email, and put it where it belongs.