Chris Webb has a great blog post on how to use the SSAS Profiler tracer to capture the MDX queries that are being run. He then uses the SSIS Term Lookup transform to filter the data he wants. Great stuff for analyzing the usage of your cube.
Read the entire post here: http://cwebbbi.spaces.live.com/Blog/cns!7B84B0F2C239489A!4075.entry