As many know by now Flex has released some OLAP components. The visual components are very similar to the AdvancedDataGrid and display data in a somewhat limiting dual-axis grid. Limiting in that you will need to customized the interface to support OLAP features such as drill-down, drill-up, grouping etc. Also the components are all in-memory so you need to create flattened data sources as dataprovider sources or roll your own implementations of the IOLAP interface elements (Cube, Dimension, Query etc). We have deviated from flattening out any datasources and have actually started creating a OLAP-Flex communications library. The library run across HTTP (SOAP) using XML/A. So far the initial results are pretty fantastic. We are just testing with a Pentaho, Mondrian OLAP stack but it should not be too hard to create data sinks for Analysis Services or other XML/A implementations. Additionally we are modifying a lot of our Flex analytics tools to ingest the OLAP library and use it as a data source. The first components being released are some Toad/SQL Query browser like tools for use in executing MDX queries and browsing OLAP repositories.

Here is the intro text for the Flex 3 OLAP components:

About OLAP data grids
When working with large amounts of data, you can quickly get overwhelmed with the scope and size of the data. For example, you collect sales information for different products, in different regions, and for different customers in a typical two-dimensional spreadsheet. That spreadsheet could easily contain hundreds of rows and tens or even hundreds of columns. Extracting useful information for such a large data collection can be difficult, and trying to identify trends or other patterns in the data can be even harder.

Data visualization is a technique for examining large amounts of data in a compact format. One type of data visualization technique is to use a chart, such as a bar, column, or pie chart. Adobe® Flex® supports many types of charts. For more information, see Introduction to Charts.

Another data visualization technique is to aggregate the data in a compact format, such as in an OLAP (online analytical processing) data grid. An OLAP data grid is similar to a pivot table in Microsoft Excel. An OLAP data grid displays data aggregations in a two-dimensional grid of rows and columns, like a spreadsheet, but the data is condensed based on your aggregation settings.

Note: While the Flex OLAP data grid is similar to a pivot table, it provides a much greater set of features for aggregating data.