First off, I really like the new SQL2005 suite of products, but after converting some of my old RS2000 reports to RS2005, I have a comment.
I'm very disappointed to find out that Reporting Services 2005 is so restrictive in accessing AS cubes. I tried to use one of my pre-existing MDX queries in a new report and found out that it wouldn't accept it because the measure was in the WHERE clause.
Also, is Reporting Services ever going to deal with a native CELLSET object instead of CROSSJOINing everything? I was excited to see that RS2000 could query cubes and thought for sure that CELLSET access would be added after a 5 year dev cycle.