How many high elves are there in Wrath, and what are their role now that they have thier own faction?
The High Elves actually have a pretty strong presence, which I'm rather excited about. The High Elves (and Blood Elves to a much lesser extent) are one of my favorite Warcraft races, and it makes me sad I can't play one. Alliance FTW. Dalaran, first of all, is packed full of them. Most of them are under the banner of the Silver Covenant, an Alliance-aligned faction of High Elves that aren't too happy about the Blood Elves being given a sizable section of Dalaran.
There are also High Elves scattered throughout the Alliance forces in Northrend. There are a few of them in the 7th Legion (no, they're not all High Elves), the Argent Crusade, and just the Alliance forces overall. The fellow in charge of the Alliance contingent helping the Red Dragonflight at the Red Dragonshrine is a High Elf. He's a total badass, by the way. Check him out up there. Ashkandi is Draconic for Awesome.
Does the Cenarion Circle have any role to play in Wotlk, either as the Cenarion Circle or as a sort of offshoot faction like the Cenarion Expedition? I would of thought lorewise they would have an interest in the reaction the creatures and vegetation have had to the Lich Kings corruption in Northrend.
Well, there are a few zones that aren't implemented yet, so it's possible we'll get a more 'serious' incarnation of them than we have now. Right now we have D.E.H.T.A. A parody of PETA that is out to kill Nesingwary for his wanton slaughter of wildlife. They're... pretty much a joke, and if that's the only Cenarion Circle representation we get you're in for disappointment, and so am I. Sorry.
Can you still do level 70 dailies for gold, and do you get XP for doing them?
You can do those quests, yes. However, since you're not at the level cap they don't give nearly as much gold. Most of it is converted into experience. You get much, much more XP in Northrend. Don't bother with Quel'Danas unless you really like the atmosphere.
The final question is full of plot spoilers, so stop if you're trying very hard to avoid them for some reason!
Faction question, and to a lord nerd (sup Alex), probably an interesting one. The Knights of the Silver Hand are very likely to be a new faction, and I'm very curious as to whether they'll be Alliance-only or neutral? I know, considering factions aren't really implemented yet, this'll probably be difficult to answer, but...I must know! If they're not neutral, my blood elf will be a very, very sad paladin :(
Sup Reinard. At the end of the Death Knight questline, Tirion Fordring shows up and kicks a bunch of Scourge tail. Afterwards, he declares that the remnants of the Silver Hand that he's gathered up and the Argent Dawn are going to become one uberfaction for the war against the Lich King: The Argent Crusade. The Argent Dawn's neutrality remains, so members of the Horde have joined this faction, though they're not all Paladins. The Hand icon of the Silver Hand has been combined with the Argent Dawn's sunburst to make the awesome banner you see on the right.