This update cannot come soon enough. I've banged on about Mailbox on Twitter plenty of times and while I get that it was deprecated because everyone else adopted their core function, noone did it well enough. The Gmail app is close, but still not perfect but this is a huge step in the right direction. I often don't care where an email has come in, I just need to action it later so being able to snooze any item in any mailbox is a huge, huge win.
I finally adopted Inobx by Google late last year after trying many other clients out but that's now on the way out and everyone is being pushed back to Gmail (which is not the easiest on the eye) and this is the one feature I need to make it more than just bearable.