Before work began on World of Warcraft: Classic, it was only possible for players to experience the original World of Warcraft by using private servers, which are illegal, often have stability or corruption problems, and generally are very imperfect recreations of the authentic World of Warcraft experience. As much as Blizzard has been aware of the desires of their community, until recently it seemed impossible for them to emulate Classic servers due to the technical hurdles of essentially having to run two massively multiplayer online games side-by-side. A breakthrough was then achieved that made it possible to run Classic servers on the modern architecture of current World of Warcraft servers.
Occasionally it's also been proposed to re-randomize all the gear. We didn't have best in slot lists back then. People weren't starting out as a fresh level 1 character with a complete list of which dungeons to run at 60 in order to gear as quickly and efficiently as possible. Now, all that data is available. If gear were re-randomized then all of those lists would become useless and thing would be close to how they were. Which is a more important part of the "vanilla experience?" the fact that item X from boss Y has exactly Z stats on it, or the voyage of discovery? Personally I think that voyage is way more important. Do you remember how many points of which stat on the ring or whatever that Darkmaster Gandling drops? I don't. Would it kill your experience if the BiS for every class were in a different dungeon so people had to actually play to figure it out rather than simply consult a spreadsheet? I don't think it would. For that matter, it probably wouldn't be a bad idea to handle it intelligently so that the better gear is in later dungeons. I remember there because some weird cases where level 40ish gear was better than anything that dropped in level 60 dungeons.