Zynga has filed documents with the SEC this morning which indicates that they are planning on raising between $850 million and $1.15 billion in their public offering. This is about $15 million more than their previous estimates.

Zynga CEO Mark Pincus is preparing his company to have an initial public offering. However he is now scrambling to get back some of the stock options that he distributed from some of his early employees. According to several Wall Street Journal sources, Mark Pincus decided last year that they needed to get back some of their stock options. Pincus approached some employees and told them to either return the options or get fired.

Kleiner Perkins Caufield & Byers almost missed out on investing in Zynga. It turns out that KPCB rejected investments in Zynga… twice. Now KP partner John Doerr said “Zynga is the largest, most rapidly growing, most profitable company, with the most happy customers that Kleiner’s ever invested in over it’s life.”

At the Web 2.0 conference, Zynga CEO Mark Pincus revealed an interesting number. About 320 million people have played Zynga games thus far.

Social gaming company Zynga has hit a $5.51 billion valuation on SharesPost Inc. Given this valuation, it means that Zynga is essentially worth more than Electronic Arts. Electronic Arts is worth about $5.16 billion on the stock market.

Facebook and Zynga have made a 5 year partnership to keep Zynga’s games on the social network company’s platform. Recently it was rumored that Zynga was planning to break away from their dependence on Facebook by starting a social network of their own. This was because Facebook was taking too much of a commission from the sales of Zynga’s virtual goods.

Zynga and Facebook’s relationship with each other may be at a tumultuous point. The level of stress associated with both companies is said to be “intense.”

Zynga used to have a Pit Bull weapon on the social networking game Mafia Wars. However the animal-as-a-weapon was removed due to a request by a letter from the People for the Ethical Treatment of Animals (PETA). PETA argued that using a domestic animal as an attack dog could lead to the abuse of real-life pit bulls.