News has leaked that Alibaba Group will name its advisers for its IPO next week. At that time the approximate date of the IPO will be released.
My sources tell me Alibaba Group executives have met with five possible candidates to advise it on their IPO. Jack Ma has been very involved and Alibaba's tentatively new CEO has also been present at all meetings.
Once all sides agree to a deal, the investment bank puts together a registration statement to be filed with the SEC. This document contains information about the offering as well as company info such as financial statements, management background, any legal problems, where the money is to be used and insider holdings. The SEC then requires a cooling off period, in which they investigate and make sure all material information has been disclosed. Once the SEC approves the offering, a date (the effective date) is set when the stock will be offered to the public.