> As for the 'what's the benefit' questions.. for simply stuff it now becomes extremely easy for
> library / application developers to just include a './launch.sh' script to get an application running.
Apart from the fact that everyone is telling you that it shouldn't be used for production, which means this will always be the non-recommended way of running an application, and you still want to install a normal webserver in case you actually want to use it in production. Also, there are differences between, say, Apache and this built-in webserver, which means that code has to be written for both, although you'll only ever use a normal webserver for production.
I don't see much benefit, except for the one-off case where someone wants to see a quick demo of software on their own machine. That said: I don't think it'll hurt to have it, either.