Open Source software reaches new heights with each passing year, but hardware has yet to be given the same treatment.
Fact is, open hardware is as important as open source software. A number of the issues facing open source software and operating systems is due to lack to drivers or proprietary drivers for proprietary hardware. It is only with both open hardware and open software that a platform can truly be considered open.
CERN, the organization behind the Large Hadron Collider, has released the Open Hardware Licence, which aims to bring the benefits of open development hardware designs. It aims to be the GPL of hardware designs, although not in the sense that it gives the same rights, since hardware and software are very different things. The similarity is in principle only, as both licenses allow one to see the source / design, modify it and share it. Like the GPL, modifications too have to be under the same licence, thus perpetuating the open nature of the hardware.
With open source software if a developer finds a flaw in the software, he or she can fix the flaw, and submit a patch for the same, in the process improving their own experience and those of others who use the patched software. Why should hardware engineers not be able to do the same? With open hardware, an engineer will be able to download the schematics of the malfunctioning / faulty / un-optimal hardware, and submit a "patch" for the same, making future iterations of the hardware better for all.
Open hardware means that companies can share designs instead of wasting resources in developing the same thing in their own private bunkers. Of course, for many companies developing hardware in private bunkers will continue, this movement, just like the open source software movement, doesn't mean all companies will embrace it, or that it will happen quickly.
One big difference between open hardware and software is that unlike software, hardware is physical, and has costs associated with it. Open hardware does not mean you will get it for free, just that you are free to do whatever you want with the design. Libre, not gratis; free as in free speech not free beer.
To see what open hardware can do, look at Arduino, a successful open source hardware and software platform based on Atmel microcontrollers. It has managed to garner a large community of hardware and software engineers and hobbyists into creating marvelous designs, and is even the hardware platform of choice for Andorid's new Open Accessory Development Kit.