Warlock info:
Soul Well will have 25 charges in the next patch.
Druid Info:
The design is for bears to be viable, end-game main tanks. The design is for cats to be viable, end-game melee dps. In both cases you are going to need the right talents, good gear, skill and companions who can back you up -- I don't mean to imply raiding will be easy.
If you want to do a little tanking and dps, you probably won't be as optimal at either, though you'll probably always be better at switching between the two than other classes. In order to be as good at tanking as the other classes, you might have to give up a few talents that maximize your dps, and vice versa. This is a good thing -- it lets you choose to actually be a main tank.
We are adding a new class to Lich King, as well as improving the raid viability of specs such as Arcane mage, Survival hunter and Balance druid. That means you have 30 available specs for 25 slots. There are two ways to design around this problem. One is that there are 25 mandatory specs and 5 that shouldn't be raiding. Boo. A more fun, interesting and ultimately fair direction is that you actually have some choices in who to bring. Imagine running a raid with no warrior tanks at all.
Don't worry about your bears. The armor and other changes were done to fix itemization issues, not to nerf druids. You've already gotten the ability to drink pots in bear form and benefit from weapon enchants and windfury. We have plenty of knobs to turn to make sure you can do your job even better than you could in LK.
On Death Knight Tanking:
Part of the reason we chose to add the death knight to Wrath of the Lich King was because groups seemed to have trouble getting tanks. We think tanking in general will be more popular if it's more fun. Improving the dps of tanks will certainly help, which is something we're trying to do to the 3 existing tanking classes through talents and gear changes.
With death knights, we are taking that a step further and trying to allow death knight with different specs to still be viable tanks. Maybe a death knight tank won't burn out if they can try a completely different tree without giving up their tanking role. Maybe death knight off-tanks can still contribute decent dps and utility when not tanking. Maybe it will just be more fun for everyone if you see different abilities getting used depending on who you bring along as a tank.
We admire the valiant attempts to come up with specs that cherry-pick every single tanking talent, but really that's not what you should have to do to tank. If Frost Presence reduced all damage by 95% and generated 200% more threat, it's pretty clear that a death knight could tank any boss in the game, probably trivially, with no talents spent at all. That is clearly a silly example, but my point is that there are lots of ways we can adjust the base class to be an exceptional tank without you having to be dependent on keeping Blade Barrier or Bone Armor up 100% of the time.
Should you get talents that help you tank? Absolutely. Will a paladin be a better Ulduar tank because she spent 20 talents on tanking and you only spent 6? There is no reason that has to be the case. Is that fair? I think it can be. The paladin will still be a better tank for some encounters and as long as she doesn't totally gimp her dps or healing abilities in order to take those tanking talents, we think the design can work.
Profession Changes:
-Looks like potion sickness was removed. Yay! Hope they really do intend to do away with that.