This feature is intended to allow the Application Under Test to be launched in a new browser window. This is to facilitate testing of applications that are particular about the conditions under which they are used.
This facility exists for IE, but needs to be completed for other browsers.
In addition, it is required that the means of achieving this mode of operation is abstracted all the way out to the selenium API, to avoid the manual intervention required in the early version.
SEL-8.