I made some route changes to the Horde levels 43-44 sections.  I have swapped 44 Dustwallow Marsh with 44 Desolace (the entire sections). This allowed me to do Deadmire (at lvl 43 instead of 38) and then go stop at TB to turn in Deadmire + The Black Shield at the same time, then fly quickly to do the Desolace stuff.  Doing 44 Desolace is now mandatory because I think its faster with the new routes. This will also make the level 53 grind much shorter.  I think these were great changes.
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.
Analogy: think back on riding the swings in kindergarten. Was it fun? Now, imagine going back to those swings exactly as they were, and sitting in them now, as an adult. They're too small. They don't fit. Your feet drag on the ground because they're so low to the ground. The bar over your head is low enough that you can reach out and touch it, and even at the highest the swing will go, it's only about chest high when you're standing up. It's exactly the same swing, but riding on it now is a very different experience, yes?
“To fill our pool of beta and stress test participants, we’ll be choosing dedicated players who meet select criteria from both the WoW Classic beta opt-in and the standard Warcraft beta opt-in. Participants will also need to have an active subscription or active game time on their Battle.net Account. While opting-in to the beta is the primary way to make sure you’re in the running to join the test it doesn’t guarantee an invitation to the closed beta test. We may also consider additional factors such as how long a player has been subscribed to the game so that we have the right mix of players to ensure great feedback toward making WoW Classic the very best experience for the community.”
×