The upgrade path is either
a) SCCM 2007 SP1 > R2 > SP2 or
b) SCCM 2007 SP1 > SP2 > R2
SCCM 2007 R2 is just an additional features added so you can install before or after SP2. Before you upgrade to SP2, i recommend that you perform SCCM backup first. For more info, please refer to http://www.ms4u.info/2009/07/part-106-backup-sccm.html
Once you have complete the backup, you need to uninstall existing WAIK as it is not compatible. The SCCM SP2 will run pre-requisite check and give you warning about WAIK. Then proceed to download WAIK Windows 7 from http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=696dd665-9f76-4177-a811-39c26d3b3b34
After the WAIK installation is complete, you can proceed to install SCCM SP2. The installation went smooth and complete without any error. To verify , open the Configuration Manager Console.
1. Check the version. Go to Site Database > Site Management > Your Site Code > Right Click > Properties
Make sure, it is listed as 4.00.6487.2000.
2. From the figure above, verify the SMS Provider location is displaying your SCCM computer name. I noticed the SMS Provider location is not display after the upgrade. To solve this problem, go to Start > All Program > Microsoft System Center > Configuration Manager 2007 > ConfigMgr Setup. Select
Perform site maintenance or reset this site and select Modify SMS Provider Configuration.
That should do the trick.
3. If you perform operating system deployment, make sure the default boot image has updated as well.
In System Center Configuration Manager 2007 expand the Operating System Deployment node > boot images > select your X64 / x86 boot image and review it's properties, the version should read 6.1.7600.16385. I will skip this first as i did not perform operating system yet.
Stay Tuned for more update on SCCM Upgrade.