Hmmm, well I have mixed opinions on the subject.
Overall I agree with EA. The thing to understand is that we all hate EA for a reason, their DLC gouging, their lies in advertising, the way how they produce games by committee, and buy out and destroy studios. This pretty much exists outside of that arena however, and is an issue where I think their interests actually do coincide with other developers and gamers in general. To use someone's earlier Hitler analogy, I'd say that EA is actually more evil than Hitler when you get down to it. Percentage wise Hitler was like 99% right about everything, but that 1% was totally bug nuts insane. People tend to forget that Hitler was loved internationally (man of the year) and an economic and social genius. People tend to forget about what he did to get the kind of following that he had to begin with, and how gradually leading into that insane 1% of what he stood for allowed it to get so heavily out of hand. People remember the genocides, torture, and other things, they tend to forget about Hitler's economics and social theory, and how he did things like predict and fuel the automobile industry the whole "one day everyone will have a Volkswagon" thing. EA on the other hand doesn't have anything quite as insane as Hitler, they don't want to kill anyone, but where Hitler was motivated by building what he thought was going to be a better world (as bug nuts as it was) EA is totally based around it's own, personal, benefit, and doesn't care who it hurts or what kind of ruin it brings to the industry or the world (and I say "the world" and mean it since the media EA is involved with really is the stuff of the future, and what happens now is going to matter down the road). EA is the kind of company that will literally put thousands of people on the steet in a horrible economy, not caring about what will happen to them, as long as it benefits from the desician. The intent and level of callousness is what makes the differance. "The Road To Hell Is Paved With Good Intentions", well EA doesn't actually have any good *intentions*, just entirely selfish ones. I doubt many people will understand the side point I'm trying to make here.
At any rate, EA is pure, unredeemable evil, but it's still evil with a purpose, and it's interests coincide with public interests for once. It's like the "Darth Vader" complex, there is nothing more inspiring than seeing some evil bastard who scares the hell out of you fighting on your side. Albiet there is no love or desire for redemption here.
In the long run a creator and/or their sponsor should have the right to their ideas, and control over them. I'm a big believer in things like patents, copyrights, etc... to a pretty militant degree. When a company like Zynga not only rips off the work of others, but pretty much publically revels in creating clones, that's a bad thing.
The way how the industry works right now is that companies buy up ideas, IPs, etc.. like crazy for the simple fact that they can own them and hold the rights to those concepts. This is why companies frequently sit on IPs that they have no interest in developing, it gives them options, the abillity to justify inspiration, and of course the abillity to shut down rival projects. Buying up those ideas though ultimatly DOES mean that money goes into the hands of the creators when they are purchused.
Shutting down clones might seem like a bad thing, especially when it goes past things like Zynga. Truthfully, I expect precedents like this to do a lot of damage. On the other hand one or two big companies holding all the rights to a few over-popular game generes is not entirely a bad thing because it encourages innovation, which is important in an enviroment where everyone, including many indie game makers, pretty much work within a very clearly defined box.... Shooters, metroid-vania platformers, etc...
Like it or not while EA might be evil, they have a valid point, someone pretty much invented this kind of Sim game and they obtained the rights after paying that guy for them. Zynga just trotting in and knocking off the whole thing and making major bank is not right. Of course I'd also apply this to a not of other knockoffs accross a wide spectrum.
I think that if EA wins this one and runs with the precedent it will be bad for a while in ways a lot of people aren't seeing (I expect them to use their victory against Zynga as a springboard to go up against a lot of groups), but when the smoke clears I think EA will ultimatly wind up forcing the industry as a whole to become more innovative. Zynga is one of the worst offenders when it comes to clones, but to be honest the entire gaming industry is infected with that attitude like a horrible rot, Zynga is just the group that has taken it to the most noticible extreme.