A few months ago, TDK announced the development of a 200GB Blu-ray disc. Now they have reached a point where they can produce a working prototype for demonstration purposes. While they still do not have set dates or a roadmap of when we can expect the actual release, it may encourage those waiting for it to hear the news:

"The ultra-ambitious technology roadmap for Blu-ray has now been confirmed as realistic, with landmarks such as this proving the long-term value of the format against its rivals. TDK was the first to develop a prototype 100GB recordable Blu-ray disc, and yet again, our landmark achievement in creating a 200GB disc is affirming the company’s position as a true pioneer in advancing the capabilities of optical media,” said Bruce Youmans, TDK vice president of product research & development.
While the cost of next-gen optical drives is still obscene, for businesses looking for alternative backup solutions, a single disc being able to hold a behemoth 200GB might be a perfect fit. Their 200GB technology requires a 6-layer disc, three times the layering that even the fancier current-gen optical discs use. There is a possibility that these 200GB discs will not function in existing Blu-ray drives, meaning it could be even farther off before it hits retail.