AutoCAD has been offering license switching for a while now but prior to the Inventor 2012 release, this was not possible on Inventor.
I have heard of usage scenarios where users received a temporary stand-alone license while waiting for the official network license information to arrive.
In a case like the one above, once the network license arrived, users had no other choice but to reinstall Inventor just for changing the license type.
Since Inventor 2012, you can avoid the reinstallation and change to a different license scheme after you have installed or deployed the product.
Please check out this post for details:
Thanks to the Being Inventive team.