You can now stack up multiple geoprocessing tools to run in order. The intermediate progress messages can still be seen when background processing is enabled, by expanding the Results Window. This can be the best of both worlds, as you can continue to work within ArcMap, but still see information about what step the current geoprocessing tool is on.
When the background processing completes, a less obtrusive message will appear in the lower right corner of the map document, indicating it has completed. You can control the time this message is visible under the Geoprocessing Options and adjusting the slider.
I know what you are thinking, "but where did my captivating progress dialog message go that is usually center stage on the map document?"
Well fear not fellow users! You too can return the progress dialog message to its former glory with these steps:
1. In ArcMap, open up Geoprocessing tab.
2. Select the Geoprocessing Options.
3. Uncheck the 'Enable Background Processing' radio button.
Now the next time you run a geoprocessing tool, you will see the familiar message and be captivated again.
There is more information about the background processing here.Jeff S. - Raster Support Analyst