Gotham by Gaslight was a tale set in 1889 involving a battle of wits between Batman and Jack the Ripper. The graphic novel was a big hit with me in those days. I was sadden to learn that plans for a Gotham by Gaslight game have fallen through.
While we may not get a steampunky Batman game in the near future, I still have hopes of seeing one. In the meantime, you can enjoy some of the artwork of the proposed game by Julie Farrell on her blog (link) and Kotaku (link).
Gnostalgia 
That is soooo wicked awesome.