Hi Linda,
Great questions. PDP 6.0 was the first version to support SQL Server Analysis Services 2005. However, many improvements have been made and we're up to version 6.3.2214.x if you apply the service packs for 6.3 located at download.microsoft.com.
If you have a Premier or other account with Microsoft, I recommend contacting your company or your Microsoft representative. Or, you can call 1800 Microsoft or you can visit this site to start with: http://www.microsoft.com/smallbusiness/buy/software/overview.aspx#waystobuy.
You may be entitled to upgrades based on your company's status with either ProClarity or Microsoft.
-Joey