At Computex Cooler Master is showing off a rather interesting product that might help with some of that. This is a 700 Watt PSU with a PowerLine adapter built right inside.
The new PSU will feature the traditional powerline unit built inside the housing for a standard PSU. This means that to use the power line feature you will need to run a short Ethernet cable from the LAN port on your mainboard to the LAN Port on the PSU.
This is a great design and certainly one we will be looking into once they are available.
Read more here.

The slightly quirky bit here is that Cooler Master decided to put an Ethernet port on the rear of the PSU, so you'd have to attach a cable to it and connect it to the Ethernet port on your motherboard.
We'd like to see an implementation that offers a built in USB Ethernet adaptor instead which connects to one of the USB headers on the motherboard inside the case to reduce cable clutter, but at least this is a step in the right direction for the Ethernet over power lines technology.