The new druid forms will be coming out with patch 3.2, which will be released to the PTRs within the month (most likely), and then will be released to the live servers a month or two after that. I wouldn't be surprised if 3.2 has a much faster turnaround than 3.1 did, since there won't be so much raid testing to do.
"Here's something I've been wondering: how do I know I'm seeing everything in the game (Old World, Outland, and Northrend) that's worth experiencing? I'm just in vanilla still, but the content can still be overwhelming at times and I always feel like I may be missing out on interesting or fun parts of the game, simply because I don't realize they are there."
The only thing you can really do is just play the game, make sure you've explored each zone completely, and research everything you find. Achievements will help with that somewhat in that they'll give you a direction to take your questing and group work with, but when it comes down to it all you can do is good old grunt work exploration of the game.
"Why are low level herbs so expensive?"
They're used in bulk for a lot of profession leveling. Right now no one wants to farm them really. People would much rather be farming Northrend stuff. So those that do farm them are able to put them up on the AH for a premium, and pretty much get whatever they want. I recently leveled up inscription to the 430/450 level from scratch, and there were stack of some vanilla WoW herbs going for 100g. It's kind of insane, but that's the market. I should note that this can be different depending on what server your on as well.
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