I see a use for this on tablet/convertible windows devices. As the new Samsung computer showed, having Android virtualized can add some missing pieces to Windows devices that are going to be primarily used with touch. Windows Store is rather pathetic overall. It is growing but not enough to compare in the tablet market. There are plenty of Android apps that can be replace by IE, but having a dedicated touch app would be a lot better. Having the option to pin an android app to the start screen and just use it like another app would be very useful until a native Windows version comes out. This, to me, is the only situation where it would be useful. I don't think it makes any sense to use the whole gui/setup/whatever of Android, just the apps.
And I have tried bluestacks many times and I still think it isn't that great.