There's a lot of room for a vendor to come in with open products, a pledge to maintain that open-ness, and decent integration to really take over the home automation market. I really feel like all the existing products are too proprietary to be of any interest to us home automation geeks.
But then the open source hardware stuff is almost entirely limited to 'build it yourself' boards. And sure, I could buy some Arduino and Raspberry Pi hardware (I actually have a lot of it lying around) and spend a bunch of time working on it, but then it wouldn't be a nice wall unit like my switches I have.
There's a huge open space here. It's a market just asking for someone to step in and make products.