Making SQL Server Analysis Services Accessible via HTTP (or HTTPS)

Yes this is possible. It is a scenario –at least is seems appealing to me- suitable for accessing SSAS from machines that are not in the same domain as the SSAS. SSAS understands windows users only (there is no such thing as SQL Server Authenticated users). So in order to access a SSAS instance you should either be a member of the domain SSAS belongs to or use a pass through logic via local