It looks like a good solution - streamer / DAC devices and streamer / DAC / integrated amplifier options.
However, the site is a bit light on where your music is going to be stored - it doesn't mention NAS nor PC hard drives. It does seem to need software to be running on a PC in the system at all times. If this can be installed on a NAS to avoid running a PC constantly, that would be good. If not, the need to run a PC (or Mac) isn't really a good option.
Here's the opening quote on their web site:
Simple Audio Roomplayers are the first affordable sound systems to combine HD sound and Powerline Communications technology. Now you can listen to all your digital music at the highest resolution.
Given that I've been listening to 24 bit hi-res audio in multiple rooms when required (and with different music in each room when that's required) over powerline Ethernet for about 10-11 months now, using Squeezebox Touches and just a NAS (no PC constantly powered up), I think this is perhaps a little unfair on others in the industry. I do think, however, that if Simple Audio are delivering the end to end solution that can be up and running in an hour or so by a customer, or in minutes if installed by a dealer, then that will simplify this technology for many customers who just don't want to or are not able to get their heads around what's required - then this can only be a good thing for the industry.