When I first launched WPTavern.com, I had the attitude of reviewing anything and everything when it came to WordPress. I was ignorant of the license and at the time, didn't really much care as long as the plugin or theme lived up to its claims without being a ripoff. This is why I published early on my thoughts on why WPTavern would never end up within the WordPress dashboard. Fast forward two years later and I've become pretty familiar with the GPL thanks to the numerous debates and debacles. The decision to only talk about GPL kosher stuff is two fold. Part of it is my personal decision because it eliminates a lot of head aches and the second is that it became a business decision. Matt made it very clear that if you were going to be in the dashboard of WordPress or be part of the good fight, you were going to have to only publish and advertise for things that were split GPL or 100% full GPL. While Matt prefers 100% GPL I have no problem with writing about things that are split-licensed since that is also kosher.
This is why I've always wanted to talk about OIO Publisher but never did because it was not licensed under the GPL and therefor, I couldn't cover it on WPTavern. I'm happy to see that OIO Publisher has moved into conducting business that's more in line with the license.
Simon, I suggest reading http://wp.smashingmagazine.com/2012/...ss-repository/ and seeing if you can tie in a thing or two for your business.