As to copywrite, how did ASO-Brain get round it witheir online version? They renamed it Toulose but was that it? There's obviously countless 'unofficial' expansions (most are here!) and there's a few 'based on' games available for free download on the net (Pirates and Plunder for example). Indeed there is also my own 'Solstice Wars' should I ever complete it. I guess it's a matter of how it's approached.....
Toulose gets away with it because it doesn't give away the full product for free nor does it charge for playing it. Two of the four key things copyright holders look at when debating to shut down a web site. The third thing is direct copyright infringement. The fact that they use some older scoring rules, very limited set of tiles (think they are missing around 100), changed a few keywords and changed a couple of key graphics helped them out. But the fourth item they looked at was "Good Will". That is the key to Touloses survival. Since the first 3 conditions are met, the fourth makes it "good PR" to not mess with them to much.
Also, I am willing to bet, the coders got a letter from HiG that said "If you stop here, never charge and never advertise we will leave you as is". Based on the fact the website owner refuses to even entertain code changes (even to fix bugs), is how I came to that conclusion.
As a developer with a project out on the street that is worth well in excess of $8 million, I would probably be painting a huge target on my head for HiG and RGG to come after me if I did anything of comercial quality. Which is why I haven't started anything other than some theory programs for the PC and XBox 360.
On the other hand, I do have a game design that has the "essence" of Carcassonne but is set to a modern day theme and is hex based. I am putting together a custom parts order so I can mock the game up to play and will probably order the parts next week. If play testing works out, I may start coding it as early as June.