[Andrew]

But since applications are sandboxed on the phone, there's not really a way to share data between applications. There are things we could do such as write an Inbox application that shoved its changes out to a WebDAV server, and then OmniFocus would look for those changes on launch, but that's a lot of effort for implementation and maintenance (and additional user configuration that is relatively prone to error, based on the support email we've been getting) for a user experience that is unlikely to be very satisfactory.

We're not categorically opposed to the idea - certainly we would like to improve the current user experience. But we are relatively limited in what is available to us on the phone. The more immediate priority is to improve performance, which will benefit everyone, and should at least alleviate the desire for a separate inbox application (and then there are other things we might do which could improve that experience further).