Last week I began speculating about what Facebook could announce at this year’s f8. One of the only ideas I could come up with at the time was the launch of a payment platform for developers. Last night Eric Eldon suggested that Facebook would begin testing a payments system with developers in the next few weeks. There has been a substantial amount of buzz about a payment platform for almost a year and a half now but so far only subtle changes have materialized.

The first update was posted by Facebook back in December of 2007 when the company announced that they would begin accepting applications to be part of the payment platform beta test. A year and a half later it is finally beginning to materialize. Facebook has also been testing out new forms of integrated credits including a system for rewarding users by sending them credits when writing a comment.

Facebook applications already have a huge virtual currency economy among the leading social games. Zynga for example is expected to earn over $100 million in revenue this year from their games. While not all of that revenue will be generated through virtual currencies, a decent amount is and the virtual currency market is only growing with the expansion of social games on mobile platforms.

Does that mean Facebook credits could theoretically be used on mobile platforms? In theory it’s a possiblity but considering that they haven’t even begun testing a payment platform, expecting to make mobile payments with Facebook is little more than a dream. Other platforms like hi5 have already been ratcheting up their investments into virtual goods.

While hi5 created their platform in partnership with Paymo, a mobile payment solutions provider, Facebook may be looking at partnership opportunities as well. Eric Eldon suggests that Jambool is the leading contender for a partnership agreement with Facebook stating that the company, “has put off a planned funding round while it finalizes a deal with a ‘major social network’”.

For now we’ll have to wait and see what materializes in the coming weeks.