Thomas Kejser and Denny Lee released the new Analysis Services 2008 R2 Performance Guide. This is an absolutely must read for any SSAS developer. Remember that many of the optimizations are obtained by doing a proper cube design. Thus, the paper has many best practices that improve performance by just choosing the proper way to implement a cube.
Originally appeared on: http://sqlblog.com/blogs/marco_russo/archive/2011/10/11/ssas-2008-r2-performance-guide.aspx