Two things happened yesterday, totally unrelated, but they ended up being about the same thing. One was an e-mail from a reader proposing heroic deadmines, basically creating more level 70 content by offering a level 70 version of all the old world dungeons. Sounds good, but what do you do when the level cap rises again, do you make them all level 80? The other event was a friend telling me how his guild did a touristic trip to Molten Core, because there were several people in his guild who had never been there, so they gathered 20 Karazhan raiders and kicked some ass in MC for fun. Another form of reuse for old content. Lots of people commented that it is nearly impossible to find groups for old world dungeons, so they either end up not going at all, or they cruise through at high speed with the help a level 70 character from a friend.
All of that made me happy that I played through the old world dungeons when I did it, the time when everybody was still using that content. Because doing the Deadmines either transformed to heroic, or with a level 70 guide, just isn't the same. Molten Core isn't the same at level 70. Not only is the challenge gone, but also the rewards would be considered worthless now.
If you didn't visit the Deadmines when the game was much younger and people still gathered in crowds at the entrance to form groups, you will never see them in their full glory. If you didn't raid Molten Core before the Burning Crusade, you will never get the same sort of experience we had. Sorry, you missed it. It might appear as if the Deadmines and Molten Core are still in the game, but those are just empty shadows. The Deadmines experience, or the Molten Core experience, was about going there at the appropriate level with other people of the same level, all of which were hoping to get some rewards which were cool for that level and that time. The dungeons remain, but the people are gone.
For places like the Deadmines there are possible solutions, for example cross-server instances or a better LFG system. There are still people at level 20, and if you could just gather them, you could still have fun in the Deadmines and get decent loot for your level. But places like Molten Core are lost. Even if you had 40 level 60 characters available, they'd rather go and form 8 groups for the Hellfire Ramparts, which would go a lot faster and give better rewards than forming one MC raid. Just like in real life, we can't turn back the clock.