Back in March 2010 when Yahoo! announced a distribution partnership with Zynga, I speculated it would takes months for the deal to come to fruition.

Nine months later, two of Zynga games are finally up and running on Yahoo! Yahoo! has launched and integrated Mafia Warsand FishVille on a variety of Yahoo! properties, including Yahoo! Pulse, Yahoo! Mail, Yahoo! Messenger, and of course, Yahoo! Games.

Yahoo! also launched games from OMGPOP (yea, Balloono!) and Elex (a company I am going to do more research on since I have no clue who they are).

I tested it out and the integration is nice, especially on Yahoo! Pulse, a social networked property on Yahoo! that probably <1% of their entire user base knows about. I imagine they will add more Zynga games in the future, and that CrowdStar games (and anyone else interested, such as Digital Chocolate, Playdom, Playfish, etc) are only weeks away from launching.

Similar Microsoft’s social game announcement with CrowdStar yesterday, Yahoo! is launching social games on a variety of online properties, instead of one central hub. Again, I think this is a mistake. It makes sense to integrate the games where their most connected users are, but I’m never going to go to Yahoo! Mail and think “oh wow, wouldn’t that be great to play Poker with spammer123” or any of my friends I’m emailing back and forth to.

Just as significant, Yahoo! is not promoting social games on its home page. Yahoo!’s home page is not only the most valuable property on Yahoo!, its one of the the most valuable pieces of real estate on the Internet in the world.

Here’s the litmus test for game developers and gamers as to whether Yahoo! is serious about casual and social games:

The moment Yahoo! adds a game activity stream front and center on its home page (and My Yahoo!), Yahoo! is serious about games and has a chance to become a major player.

Until that moment, partners like Zynga are only are only reaching a fragment of Yahoo! audience and social and casual games shall remain just an experiment to Yahoo!

For Yahoo!’s sake and its shareholders (e.g., me), let’s hope that Yahoo! makes this move sooner rather than later (e.g., after Facebook has eaten into Yahoo! Mail’s market share, which is one of the last unique value adds Yahoo! offers).