While we still cannot download complete V9 SDK for Dynamics 365, I just noticed that Nuget packages for V9 are available now. So those of us who need SDK assemblies to develop plugins/applications can now install those packages:
There will likely be other new features there, but one of those which would not be available in the earlier versions of the SDK is a new type for the Multi Select Option Sets:
Microsoft.Xrm.Sdk.OptionSetValueCollection
It’s, basically, a collection of OptionSet values, so there are all the usual collection methods/properties there which we can now use to work with the Multi Select Option Set attributes.
Please send me sdk file