you forgot 1 thing. People get tired of their games and all games in general. Their pipline is bone dry and people are quickly growing bored with their current set of games. Regarding the online gambling, I think that some people with a lot more money that Zynga might have a few things to say about how that goes down like say every freaking casino in Las Vegas and Atlantic City that stand to lose a lot of money if people can just sit at home and play. Remember Jack Abrmohoff? That was all about the corruption in gambling and using the government to knock off one or two competitors. You think that these Wynn enterprises is just going to say, well it was good while it lasted but Zynga has the most popular texas hold em game on facebook so why even try. You sir are not living in reality.
First, you speak of people getting tired of Zynga's games but if you check the MAU numbers it is actually the complete OPPOSITE. While the numbers dipped for a short period, Zynga has now surpassed 300,000,000 MAUs so I do not believe their pipeline is "bone dry". Also, if you do some research you will notice Horn will be releases in August 2013 and by the trailor you can tell that it has the firepower to top all of the charts once it is released. So just imagine the potential once Horn is released, since Zynga has 300 million MAUs before Horn's release.
Secondly, you would like to throw around "people with a lot more money" will have something to say. Who are they going to bully - Pincus or Zuckerberg? You tell me since you are so intelligent and in the "know". I believe if you check the list of the world's richest people you will find Zynga's CEO Mark Pincus on there. So, "all knowing one", can you please tell me who is going to step up and tell Zynga what they can or cannot do?
It seems that you can not post facts so you just post nonsense.
The fact is MAU are up because of their business model. If you actually spent any real time on facebook you would know that the basic model of these games is to get "players" to request junk from their friends who then start playing too. The problem, with this model is that all the friends have gotten sick and tired of send me a blah blah blah for my farm or whatever the hell and facebook makes this easy by giving the user the ability to simply block all requests from that game. What this has led to is a small number of people creating several accounts to send themselves crap back and forth.
Regarding Horn, I think that will go the same way as EA did with SimCity and several other highly anticipated games like it, down the toilet. The fact is nobody has made a way to come up a viable way to make money off these people, and Zynga is right when they say that there is a hole in the 'real games for gamers market' in particular the RPG games, but they are not the only ones who have noticed this hole and they are certainly one of the last ones to get to the party (see games like battefeild, battle field pirates, the Avengers and so on). Why don't you take a look at those games and see how well they have fared? Or I can save you the trouble and tell you they are bombing, big time.
Regarding the online gambline if you think that Pinicus and Zuckerberg being some of the richest people in the world has anything to do with it, you are crazy. Even if they could fend off the largest of them, no way they are going to fend off everyone that spents billions of dollars building resort casinos that will now be basically worthless. If online gambling does become legal it will be through the gambling commission which is wholly controlled by the Casinos. I guarantee you they will build in natural entrance barriers to keep geeks like Zuckerberburg and Pienus out of their pie.