A recent blog by TK Anand at Microsoft is a very important read for those of us who live in the MDX query language space.  TK is outlining the future of Microsoft Analysis Services, MDX, DAX, and the BISM (BI Semantic Model).  The MDX query language is the de-facto OLAP query language standard used by companies including Microsoft, Oracle, Teradata, SAP, and Kognitio.  Microsoft has been the leader of this standard and it is important to carefully watch the direction they are going in.  I strongly suggest you read this blog post: http://blogs.msdn.com/b/analysisservices/archive/2011/05/16/analysis-services-vision-amp-roadmap-update.aspx.  Of course, nothing happens overnight and there is an entire ecosystem around the MDX query language that will have to understand what Microsoft is doing and determine how they will move based on this.  It will also be very important to see how Excel (the most ubiquitous BI tool) responds to these changes in Analysis Services.