The idea of the 6x00 as a radio appliance, to which software can connect to provide a range of functionality is extremely appealing to me.
I can imagine software to operate (possibly on currently unsupported platforms like the Mac and Apple's iDevices) of course, but also scanning and monitoring software. As is often the case, imagined possibilities will be practically bounded by engineering constraints, but this should be a huge step up from what is possible with the last generation of radios.
Commensurately, I'm really hoping to get early access to the 6x00 API. I gather that Steve Hicks N5AC (VP Engineering at Flex) has already provided access to a few lucky external developers. His posts on Flex's new Support Community suggest that he is open to the prospect, though I gather there are caveats about the changing nature of the API and the fact that it is, as yet, undocumented.
I have an email into Steve enquiring whether he would be willing to provide API access.
Separately, another community member Stu Phillips K6TU has had access to the API for a while and has been working on an iPad app for operating the radio. As part of that project he has allegedly created Objective-C bindings to the API with some nice class wrappers representing major entities. This sounds awesome and he is claiming to be close to being able to release these in some form for the community at large. As a Mac user this is music to my ears. Hopefully a library package of this sort would make getting started extremely easy and convenient. Assuming reasonable coverage of the API capabilities, I could see myself being quite happy to get started with this and maybe this would be the basis of some app projects.
However, as competent with Objective-C as I am, I am hoping I can still get access to the native API as I have plans to write Haskell bindings and then create apps with the cross-platform GTK+ GUI library. This will allow apps to run on Windows, Mac and Linux and there are even builds of GTK that absolve the need for X11 (not historically a problem on Linux, but not so great on Windows and the Mac where you'd like the app to appear as native as possible).