Nope. This is for connecting your devices in other rooms to your router/switch, so that you don't have to pull ethernet cable all over the house. It won't give you internet magically from some unknown place. You may ask, why not use wireless instead? Powerline ethernet is generally more stable with little fluctuate in speeds and no drop outs.
Also, regarding the multiple circuits, these new ones definitely work (albeit at a slower speed). My Netgear XAVB2001 gives me 8MB/s (~64mbps) on the same phase and 2.1 MB/s on a different circuit.
If you plug into a hotel room and I assume you have two.. others shouldn't be accessing it if you turned encryption on. If encryption is not turned on, you still have a limit of adapters that can communicate.. limit is 16.
Can't wait for these badboys.