Current Yahoo! CEO Jerry Yang has announced today he is stepping down and returning to his former role as Chief Yahoo!

The news ends an embattled tenure for the Yahoo co-founder, who took over as CEO in June 2007, replacing then CEO Terry Semel.

Now the big question is what does this mean for the still lingering merger/partnership/take-over with Yahoo and partnership with Microsoft. Yahoo is not doing so well, the stock has already lost nearly 2/3 (closed today  @ $10.63 per share) of it value since the take-over was announced. Back on February 1st Yahoo! stock shot up to $28.32 per share from $19.18 the day prior. Recall about a month ago Yahoo was urged to sell itself to Microsoft for $22 a share.

Further there is no immediate word as to when a successor for Yang will be appointed.

Yahoo! Inc. (Nasdaq:YHOO) today announced that its Board of Directors has initiated a search for a new Chief Executive Officer. Jerry Yang, co-Founder of Yahoo!, has decided to return to his former role as Chief Yahoo! upon the appointment of his successor as CEO, and he will also continue to serve on the Board. Yang, 40, assumed the CEO role at the Board’s request in June 2007, and he has led Yahoo! through a strategic repositioning and transformation of its platform.

News Source: Microsoft Blog