Enriching CRM data using a csv file and out of the box data import

So how is this done you say … and was this not a feature that was turned off pre version 4 launch??
The secret feature revealed ….
Step 1
Build an Advanced Find view of the records that you wish to enrich and the columns that you wish to update
Step 2
Export the view to Dynamic Excel
Step 3
Select all coumns and right click and unhide columns
Step 4
Move the last column with GUID to the first column and change the name of the column to the entity name in this case Contact
Step 5
Save the file as a csv file
Step 6
Import the csv file via the import menu
Step 7
Choose the csv file 
Step 8
Select Next and you will now see a new option at top of screen “Enrich data …”. Leave this clicked and the data map should have defaulted to automatic.
Step 9
Select Next and ensure Import Duplicates is checked
Step 10
Complete the import wizard and wait for import to complete
Step 11
Review data exported and review the updated records. That Simple!!!
UPDATE: Change to process after Rollup 9
Please not that after installing rollup 9 you are no longer requried to insert column A and copy the last column to it (Step 4). This column is already populated with the GUID of the record type. Just leave it as is and change the values in the other columns to enrich the data.

CRM5 Preview from the CRM UK Blog

This is a great blog on the new features of CRM5.