Provide an SDK for UCWA
Unified Communications Web APIs are available since more than two years now, and earlier this year they've been (finally) enabled on O365 as well.
Still, as of today, there's no official SDK provided from MS to interact with UCWA.
There are concepts in UCWA that are quite unique or not obvious at all: such as working with the Event Channel; for which there are no good working examples, or sufficient documentation.
More often we hear during presentations speakers saying: "... but because we're not animal, there's a package/library for that!"
I still consider myself an animal, but I would like anyway to have proper documentation and an SDK to work with; while building my solutions targeting Skype for Business. In the same way I can do today already while targeting SharePoint or many other 365 services, for example.