Following all the acquisition mania in the BI marketplace last year, it's interesting to see that the Microsoft approach of growing your own BI platform seems to be paying off according to this article by Gartner in Information Week.
It has taken a while though - I well remember my first foray into olap services in SQL Server 7.0, we were using a market leading olap tool to build a cube from a fact table with 75 million rows in for an electricity company. It was taking 26 hours to build and then failed and we used the same hardware and SQL Server 7.0 olap services to build the same cube and it successfully completed processing after three hours, and because it was an open solution we were able to use the same front-end for the users.
That was in 1999 and since then there has been loads of work on the Microsoft BI platform so by last year I worked on a project that could load 15 millions rows of new fact data a night into a cube with two years of history.
In the latest version there aren't the big changes that we saw moving from 2000 to 2005 as the hard work was done then. However as I have posted before the key things are analysis services 2008 are:
The key white paper on these new SQL Server 2008 analysis services features is here.