I think what YHOO and Alibaba agreed upon as stated in the letter of agreement is that likely IPO is mid next year but Alibaba has the right to be the first buyer of YHOO stakes if YHOO decided to sell it. For obvious reasson, like many said here, the longer Jack Ma hold off the IPO the better for YHOO getting a good premium. Ken Goldman will maximiize YHOO Asian investment getting every penny premium. YHOO to mid $20's.
Sentiment: Strong Buy
The only mention of an IPO and a date in the letter of agreement is; #If a Qualified IPO has not occurred by December 31, 2015, Yahoo! shall only be required to sell such Shares as it owns at the time of a Qualified IPO.#
And anyone who remembers AliPay does not think that waiting is good for anybody other than Jack Ma. --Take the money and run or Jack Ma will do it-- is a valid concern.