In the meantime, these documents have been made available to the public that had been classified Confidential originally. They talk about releasing Internet Explorer 9 Beta from August 2010 onwards. At this time, preparations at Microsoft’s OEM partners should begin, too.
However, the documents are dated 20 April 2010, so the information contained in them may well have changed in the meantime due to delays. Furthermore, there is an explicit note that these are preliminary plannings.
Possible dates for Release Candidates of Internet Explorer 9 have not yet been set, neither is there a date for its RTM. For both cases, decisions will be taken only after the beta.