One of the problems however, I feel should be clarified, is that while the Estate apparently has nabbed rights to the trademark, they do not have any rights to the Blackmoor setting, anymore than the Gygax Estate has rights to the Greyhawk settings or D&D.
The Estate has nabbed the trademark, and apparently WoTC felt it prudent to change the name of Blackmoor to Arn, but there's a lot up in the air. They don't appear to have IP rights, and a lot of this stuff was done with agreements with WoTC, along with (perhaps) Dave Arneson's approval. Note the press release doesn't say anything about legality. For all we know, this could be covered in another old contract.
I'm going to provide some links for folks. Like anything else, it's always easy to look at one press release and immediately take sides, but there's probably a more complex dynamic here:
Background on some of the rights:
[Blackmoor5e] Age of the Wolf to be released for free after 15 years! - The Piazza
Some thoughts on the trademarks from a few site:
The Blackmoor Trademark has been claimed by the David Arneson Estate and has been licensed to the company called Fellowship of the Thing Ltd. The company has previously created the documentary
odd74.proboards.com
The company known as The Fellowship of the Thing, creators of the documentary Secrets of Blackmoor are looking to expand their business int...
blackmoormystara.blogspot.com
Some additional background -- a few folks have found the people who are overseeing the estate might be a little too, shall we say, "aggressive", in their claims of ownership, opinions from folks who knew Dave back in the day.
Bad Actors Slandering Tonisborg - Page 2
www.therpgsite.com
I don't know who's in the right, but I do believe that (a) people need to do enough independent research first before rushing to judgement, and (b) it's probably not a good idea for the fight to be done with press releases.