EBay announced plans on Tuesday to spin off VOIP company Skype, with an IPO planned for the first half of 2010, leaving analysts busy figuring out how much the public company will be worth.

Gabelli analyst Robert Haley estimates that Skype will be worth $1.5 billion to $2 billion as a publicly traded company. But by signaling an IPO for Skype, eBay could be flooded with a number of potential acquirers, like Microsoft, Google, and social networking site, Facebook, Haley wrote in a research note.

Analysts have speculated that Skype could also find itself in the crosshairs of a host of companies, like Microsoft (MSFT), Google (GOOG), and social network Facebook.

Google, Haley said, could integrate Skype into everything from Gmail to search to Google Talk, while Microsoft could incorporate Skype into Windows Sharepoint.

Meanwhile, IPO analyst Tom Taulli was far more bullish and said a Skype IPO could fetch $3 billion to $5 billion, assuming that the IPO market recovers as expected later this year.

William Blair analyst Jack Murphy is also in agreement with Haley on the possibility of Skype being snatched up by another company.

We believe that (eBay) management has been actively looking for buyers, but concluded that a Skype IPO would create the most value for eBay shareholders. While management plans on a 2010 IPO, we would not be surprised if a private market deal transpired first, Blair wrote in an analyst note.

Skype sales surged 44%, to $551 million, last year and the company expects them to top $1 billion in 2011. The user base surged 47%, to 405 million, in 2008. eBay has said it expects Skype to be a billion-dollar company by 2011, nearly doubling 2008 revenues. However, eBay has written Skype down to $1.7 billion on its books.