Technically yes, but I wouldn't recommend it. You'll need a lot of help to do it. By help I mean people who are willing to summon you into Icecrown and protect you while you get to the altar needed to craft the cloth. If you have really good friends willing to do that for you, go for it. If not? Don't bother. Just wait until you can fly.
I remember a Story about how there would be a overhaul to Mining, so you wouldn't have to run to Elwynn forest to get those Copper Nodes to level up. What ever happen to that?
This actually did happen to some extent. They wanted to make it easier to skill up Mining, and they did. You get skillups from Smelting longer than you did before. Smelting Copper doesn't go grey before you can even mine Tin anymore, for example. You can't avoid mining entirely (unless you spend a whole lot of money on the auction house) but skilling should be much faster than it used to be.
This might be a bit early for this question, but my question is about heirloom items. They are useful for leveling alts, but what will they be worth after Wrath? Will heirloom items still scale with you when you will be leveling to 90 in a couple of years and will you still get the experience bonus from the shoulders or will they stop being useful after level 80?
Yeah, it's a bit early for that one. We just don't know, and I bet Blizzard doesn't know either. That's probably something we won't find out until the beta of whatever the next expansion is, and that's a long ways off. If they scale up to level 90 they'll probably end up far inferior to actual level 90 blues. They sort of need to be for people to want to do 5-man dungeons.
I remember hearing that they were going to do to tabards what they did to Badges of Justice or vanity pets. Is there still a plan to keep tabards from taking up bag space?
The more common tabards can be thrown away and repurchased at tabard vendors in major cities, so there's that. I don't think they plan on doing something like they did with vanity pets, they just made it easier to get rid of them and get new ones without feeling bad about it. It will still cost you a bit, but you don't really need to keep thousands of tabards around anyway, even for the achievement. Once the tabard has been registered as you owning it at one time, it counts forever.