Yes, this new feature is fantastic 
- combined draft
- assign color to Smart folder and Drafts
I still think that a "Combined Deleted" folder would be great also.
Thank you Kostya
I am curious why would people want to have a "combined deleted" folder?
I personally don't like and don't use even a combined inbox, but I understand why some people with a different workflow than mine might want to use that.
I somewhat understand some rational behind a combined draft folder, but even that sounds more of an adornment than real functionality. But what is useful in a combined "deleted" folder?
It is not something that you are checking or looking into regularly (or at all?). I don't think I've ever looked in the deleted folder in Aquamail. And the only reason I can see one might want to look into that folder is when something was deleted by mistake. (And except for Gmail accounts, I delete messages without that "buffer". I also do not use "recycle bin" in Windows.)
Can you describe some scenario/use case where that is really helpful?
And just in case, - I have nothing against it, as long as it is not forced upon all users (and that doesn't seem to happen any time soon, based on Kostya's attitude toward flexibility of options). -- It is just my natural curiosity that has been demanding answers for about a day now, since I've read your posting yesterday.