One thing we have learned from past expansions is the significance of preparation. This could mean stockpiling supplies or cleaning out the bank of crap.
So Kir is a JCer, miner, fisher and chef. Now, if I didn't have mining, I would be stock piling epic gems like crazy. However, knowing that I will be stopping at every node I come across, finding gems won't be a problem. Same with cooking, since fishing and killing things for materials go hand in hand with making food. I can't bring myself to do the dailies so I will just level cooking and fishing together.
I suggest taking a look at your own person time and energy. Since information is still slow to come in for various tradeskills, it may be hard to map out a good leveling plan.
If you fish, save fishing hooks and water walking potions. Since I am not in beta, I don't know how annoying it will be to try reaching certain pools, but it doesn't hurt to be prepared.
If you don't fish but still cook, it may be worth it to do the cooking dailies if you stopped. Things like Hearty Rhino and Mega Mammoth Meals look to be good until 450 skill but still need spices.
If you use ores, the prices aren't super low yet (at least on my server) so it may be worth it to mine several stacks if you are able. Otherwise, wait for the clearance sale at your local auction house as Cata gets closer.
Herbs are probably still at crazy prices, like they are for my server. Again, if you can get your own flowers, great. Otherwise, bribe a friend or watch the AH.
Books of Glyph Mastery seem to be a hot item as well. I wish I understood inscription better to give any insight.
Most people have a bank alt for dumping stuff in. Now is a great time to go through it and get rid of things have become obsolete recently to make room for the new stuff. Clear your main bank of outdated things (like any idols you were hanging on to because of their now defunct perks) and start moving some old tradeskill items to an alt.
It looks like the first new bag will be 22 slots, same as the current Glacial bag. Some folks have the cash and already have larger bags. Others have tailor friends or alts. With all this in mind, you may or may not want to wait on upgrading your bags.
A note on Scrolls
Since they changed scrolls to work as a battle elixir, it may not be a bad idea to stock pile those along side foods and potions. Always helpful when working those early dungeons and questing to have a little boost until the better stuff is available.
As you may have noticed, I changed the banner. However, as you may have also noticed, I suck at formating and such. While I tweak with things a bit more on the blog, bear (ha) with me.
In the meantime, what are you doing to get ready for leveling?