Perhaps Dropbox will open source the project and the community can keep developing features and maintaining it.
It doesn't matter how much you are going to pay, someone paid more (Dropbox) and now they want exclusivity on the garbage can they are going to put this in.
I would love to see more companies shutting down services open sourcing them, but it's a lot of work and once you decide to shut something down you want to also cut the losses.
Unfortunately not. We gave a lot of thought to open-sourcing the underlying system, but this is ultimately not something we will support."
When mailbox goes, I'll probably drop my dropbox subscription as well.