Just found this article on "tssz".
A sega employee discusses the companies future projects. Interestingly, Shenmue 1 HD is mentioned to be released in winter. The second game will follow if it does well.
Remember this is a rumour, so credibility is really 0 at best.
Still if it is true, least it gives us a possible release date.
http://www.tssznews.com/2012/05/19/rumor-alert-anonymous-sega-employees-discuss-projects/