As mentioned in my last post or so, the other major offering in the GSL is Amethyst Foundations. Unlike previous offerings which are adventures (that appeal to me most), Amethyst is a setting. Settings have a much higher hurdle to get over in the GSL, than they did in the OGL, due to a thing called the DDI. So many 4e players have become comfortable with the DDI that a product that adds mechanical information that isn't on the DDI is less appealing.
So how does Amethyst fare? It fares well IMO. The DDI issue remains but the nature of the product is such that it is worthwhile. Some of this arises due to Amethyst covering new material that you can't get in the DDI anyway, such as modern classes and equipment. Some of this arises simply from the fact that the mechanical additions are good quality and flavourful. There are some qulaity issues with the designer not quite getting 4e's design, but nothing fatal. I am very interested to see how some of these things will play out. I can already envisage movie like gun-fu with 40K like tech simply from a read through.
Finally, and mostly importantly, is that the setting is actually interesting. I would have been interested in this as a setting for True 20 or Savage Worlds. It is our world in the (unspecified) future. Humanity suffered an almost extinction level event which saw the return of magic as a fae realm coexisted with ours. Technology and magic continue to be in conflict.
From a short summary, I can see how this sounds cliched, but it is well handled. The imagery and text provides a consistent image and world view. This is not merely D&D through into our world but a very specific vision that encompasses a lot of popular ideas and genres. I personally liked how the fae world had a specific flavour that wasn't generic or cliched. Without meaning to turn people off, it reminded me of many cool anime shows I like (Wolf's Rain, Last Exile, Claymore to name a few) which have a highly visual, flexible, and flavourful setting.
When words fail, turn to pics (and these are by no means the best ones):
Overall, Amethyst looks like a very solid offering in the GSL for settings. I hope we see more of it.