The thing that sets the Pi apart for me is that is actually has some I/O broken out right on the board, which makes it much more suitable for things like robotics and automation. The things you mention can be done better with different hardware imho.
Pi doesn't have Wi-Fi, if you want to do ad-hoc Wi-Fi stuff I would suggest you get a cheap Linux-based router. If you want a video player, you can get cheap Android-based ones for ~50 bucks (i.e. http://www.dealextreme.com/p/mini-android-4-0-network-media-...).
Pi doesn't have Wi-Fi, if you want to do ad-hoc Wi-Fi stuff I would suggest you get a cheap Linux-based router. If you want a video player, you can get cheap Android-based ones for ~50 bucks (i.e. http://www.dealextreme.com/p/mini-android-4-0-network-media-...).