Great news, Microsoft just released the System Center Management Pack for SQL Server 2012 Analysis Services. What is in it:
System Center Operations Manager (SCOM) is a cross-platform data center management system that provides health and performance monitoring of systems and services. This management pack extends SCOM to include Analysis services monitoring capabilities. BI Management packs have been a constant redzone ASK from CSS and the external community, and the AS management pack is the first MP delivered from the BI MP suite.
These management packs offer the following benefits
• Simplified experience for discovery of Analysis Services Instances ( 2008 [Multidimensional, PowerPivot], 2012 [Multidimensional, PowerPivot, Tabular])
• Performance monitoring for Instances, Databases and Partitions
• Space monitoring for Instances, Databases and Partitions
• Extensive performance collection for memory, CPU and I/O utilization
• Ability to define custom thresholds for each monitor to configure warning and critical alerts
• Detailed knowledge to guide the IT operator in resolving problems
Download it here.