Folks, it's here!  Microsoft released Update Rollup 5 for Dynamics CRM 4.0 today.  You can read about it here:

http://support.microsoft.com/default.aspx?kbid=970141

And download here:

http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=5101d801-976b-4c11-bdfc-000b970ef4a3

As with all other rollups, this one is cumulative.  That means you don't need to apply Update Rollup 1-4 first.  So if you are at UR 2 or 3, or even RTM code, you can just apply these updates and you are - ummm - up to date!

Some things to note, just like with other rollups:

• There are updates for the CRM Server, Email Router, SRS Data Connector, the CRM Outlook Add-in, the Data Migration Manager and MUI
• You do not need to apply them all at the same time.  This means you can apply the client rollup as you plan out your server update, etc
• You will definitely want to test this update in a Development environment that mirrors your Production environment
• Make sure you back up your CRM databases, and any custom code you may not have stored in the CRM database prior to applying the update.  You can uninstall if you need - but it's still better safe than sorry
• There are several hotfixes that need to be manually configured in the update.  You can read about those in the KB article above

Update Rollup 5 is in line with Microsoft's plan to release cumulative updates for Microsoft Dynamics CRM 4.0 every 8 weeks or so.  Since UR1, they have been on target for this.  This affords IT departments to plan for and test the latest fixes for CRM, instead of just applying ad-hoc.  If you do experience an issue that has not been addressed by a current fix, and it's determined you NEED a hotfix to resolve the issue, Microsoft will work to release something to you in between rollups.  They still regression test these ad-hoc fixes before releasing them to customers in all but the most extreme of situations/issues.  And most likely the fix will be included in the NEXT rollup for CRM.

Happy testing!