That sounds nifty. Could you provide an end to end flow for what you'd like to do? We'll be opening up the platform for partners to add extensions soon, maybe this is a good candidate.
Ideally it'd be cool to provide some sort of custom designed function in Excel that is hosted in Azure. So I could write some C#(Eventually F#! Woot!) and then link it into a worksheet I have. So I could write a function like: getTheWeatherByZip and then in excel call it and get say a string back with the weather.
Hopefully that makes sense.