According to Anime News Network, the Mysterious Cities Of Gold is coming out on DVD here in the UK in February 2008! I really loved this TV series when I was a child! My boyfriend has already volunteered to get me a copy for my birthday. :D
As it doesn't say otherwise, I expect this release to be English-language only, which would be great - as I remember. It was good in English, a similar cast to Ulysses 31 (which is another superb series I'd recommend to anyone), but, I'd also love to hear this in Japanese. Why? Because Sasaki Isao is playing Mendoza. ^_^ Nozawa Masako (most of the Dragon Ball universe saiyajin, and hundreds of other leading roles) is playing Esteban, too. ^_^
It probably can't be multi-language, though, since the differences between the English, Japanese and French versions of this series are all a little different... even the UK and US versions are different...! -_-;;