Every company seems to share a different level of detail regarding their feasibility studies. At a bare minimum, most companies provide the size of the mine (the milling rate) and the estimated completion date of the feasibility study.
Here are a couple of samples of the info that other companies have shared about their feasibility studies.
Nevada Copper
June 2012 - By October 2012 a feasibility study will be released that will consider a staged development process with a review of a stand-alone 5,000 to 7,500 ton per day high grade underground mine and mill
Sept 2012 - The production rate has now been established at 6,500 tons per day, sufficient for a 12 year initial mine life. Release of the feasibility study results is anticipated for October 2012.
Nov 2012 - Nevada Copper Announces Positive Feasibility Study Results For Stage 1 Underground Mine
Pretium Resources
Feb 2012 - "We announced the initiation of a feasibility study on the high grade
opportunity at our Brucejack Project, expected to be completed by the end of 2012"
Sept 2012 - "We had decided to advance the feasibility study on the basis that the flotation concentrate will be sold to third parties rather than refined to produce doré on site."
Oct 2012 - "The feasibility study ... is being advanced with an operating rate of 2,700 tonnes per day and ... is expected to be completed in the second quarter of 2013."
In addition, they've announced estimated capital costs, operating costs, and the development schedule in conference calls.