The SSAS features available in Web Analysis Studio are:
Suppress Missing data or zero
Select ID/member vs Description/Alias per dimension
Multiple Hierarchies
Ragged Hierarchies
Linked Cubes
Large Dimensions (1-Million+ Members — that is, more than 1 million members)
Cell-Level & Dimension-Level Security
Data Mining & Mining Dimensions
Connection Pooling
MSAS 2005 Aggregates
Local Cube support
Server-side Top/Bottom and Hierarchical Sort