I'm just gonna leave that right up there.
"Maybe I missed it, but do we know how much flying is going to cost in the Old World when Cataclysm?"
Blizzard has said a few times that flying in the old world will not require any sort of "Cold Weather Flying"-like activation; you'll be able to fly around Stormwind and Orgrimmar as soon as Blizzard enables it (and we don't know when that will be exactly). 310% flying speed will cost something, though, and we don't know what that'll be, either.
"Are there weapon skill-ups anymore? Do I need to spend time whacking low-level mobs to level up my 1-handed sword skill so I can tank properly?"
Nope, weapon skills have been removed from the game in Cataclysm. And thank god, too ... I'm really tired of leveling up my alts' weapon skills. My rogue just got the 232 heroic dungeon axe, and it's been very annoying so far having to level it up.
Highlight also asked:
"Do characters start out with all possible weapon proficiencies for their classes, or must they run to the appropriate weapon master? For example, my Worgen hunter starts with a gun, but if I wanted to use my Heirloom Bow, would I have to run to weapon master to train Bows? Or do I start with the skill immediately?"
Proficiencies are gone as well. If you can use the weapon, you can equip it and start killing things with it right away, with no steps in between.
"As far as you're aware, will the servers be able to support purchasing and installing from the online client on Cataclysm release date?"
We don't know if Cataclysm will be available for digital distribution right away at release. Blizzard has not said anything yet, and it likely won't until we hear when the actual release date will be. I wouldn't expect Blizzard to offer it right away, though. The huge world-wide midnight releases are a gigantic PR opportunity, one that it'd be silly to allow to go away.
Have questions about the World of Warcraft? The WoW.com crew is here with The Queue, our daily Q&A column. Leave your questions in the comments, and we'll do our best to answer 'em!