depends on the QA team?

A lot of the testing I do requires multiple applicatons and differnt versions of the same app at differing times.
By using SWV I am able to create my base image and then pick and choose which app and which gets installed when.  in my experience, a typical MS Office install can take 20 minutes ro so.  I do this ocne and now it only take 30 seconds. Plus when I deactivate the layer I know that all of the application is gone, no worries about there being leftover stuff  from an uninstall. 

You can do the math here: In the past I could spend up to 4 hours getting a base system setup with all the apps needed for a basic test.  Now that 4 hours takes less than 15 minutes from start to finish. Uninstalls take less than 15 seconds and the system is clean.

...I don't think so, unless Office is already imported into the workstation when you say the "install" starts.  Also, wouldn't you have a base image that you would deploy, not build from scratch?

In general, you don't have to QA apps vs. existing apps as much, but I have come across multiple issues where certain apps (like Office) will interfere with similar apps, so testing is still necessary.  SWV seems like it will save time on the whole, but as with any repackaging job, you need to test all functionality of a repackaged application to guarantee no functionality is lost.