Skype, how many downloads?

1.2 billion downloads of the Skype client, or only half of that?

Data from the Skype RSS feeds:

• March 17, 13h45 GMT: 1,168,075,188 downloads
• March 27, 23h20 GMT: 628,899,379 downloads
• April 07, 09h15 GMT: 647,446,472 downloads

On September 28, 2008 Josh Silverman claimed: “Celebrating 1 billion downloads”.

So, Skype, what should we believe?