The news of Yang’s retirement has been welcomed by Wall Street with shares in the internet company jumping around 12% in early morning trading, to a total tune of $1.83 billion. Obviously Wall Street feels that Yahoo is much better off without the original Yahoo member.

Having only accepted the position of CEO in June 2007, Yang has had a very short career at the helm of Yahoo. During that time he has come under much criticism, mainly for his rejection of the original Microsoft offer and the downward spiral of the company’s shares.

In his blog, however, Yang discusses his reasons for leaving and although he recognises the difficulties over the past few months, he reminds readers of the changes that he has brought to the search engine – as CEO he led the search engine through the re-wiring of its entire network, and the partnerships the company has made with developers and publishers. He also mentions that Yahoo was seen to be the place where users turn for information on the Olympics and elections.

Yang will now step down to Chief Yahoo and focus on “global strategy, product excellence, technology innovation, and working with the Board and our executive team to help Yahoo realize its full potential.”

Naturally, the next wave of speculation will be on whom the new CEO will be and whether or not that person will be ready to do a deal with Microsoft, which analysts believe is the only long-term strategy for Yahoo.