(UPDATE: Too many corrections were needed, so we're rewriting the entire post.)
There has been some confusion on the question of English-language subtitles on the Japanese Blu-Ray release of Lupin III: The Castle of Cagliostro. Some sources say yes, some say no. Fortunately, the experts have weighed in to settle the matter, once and for all.
First, we need to specify which Castle of Cagliostro BD we are talking about. Studio Ghibli released two separate versions: a single-disc release, with the same package design as their feature film library. The second release is included in the massive box set, "The Complete Works of Director Hayao Miyazaki." More notably, all films in the box set were given an all-new digital remaster, different from the masters used for the single Blu-Ray packages.
So, the $64,000 Question...does either version of Cagliostro include English subtitles? Reed Nelson, anime scholar and Discotek Media's resident Lupin III expert, weighs in:
There are two Ghibli Blu-Rays of this movie. There's one that's part of the Miyazaki collection and another that's just a standalone Ghibli ga Ippai disc.
The Miyazaki collection version has zero extras and zero English. Nothing at all. But it does have the Remaster footage.
The standalone Ghibli BD that came a couple months later (kinda fuzzy on the release date) has neither of the English dubs on it, but it DOES have a brand-new English subtitle track and a few extra features. The subs are pretty good but they're a bit minimalist.
Much thanks to Reed for clearing that up. I read a reader review on YesAsia that boasted the single-disc Cagliostro included the 1980s Streamline Pictures dub, but no subtitles. It appears that person was incorrect. And online retailers often get these details wrong (since the appeal is only for importing fans). Much of the time, one has to wait until they hold the physical package in their hands to answer these questions.
For the North American market, Discotek's newly-released Castle of Cagliostro DVD includes the 1992 Streamline dub, two versions of the 2000 Manga Entertainment dub (the second being a "family friendly" edit that removes the unnecessary profanity), and the Japanese soundtrack with newly translated English subtitles. For Miyazaki and Lupin fans, this is the one to get.