That's enough of that, though. On with the questions!
I remember reading during Wrath beta that at the end of inscription scribes were going to get a 7th glyph slot, what happened to that? Did it get scrapped completely or will it come with a later patch?
The 7th glyph slot is gone, and in its place is some supercharged shoulder enchants. They're better than the ones offered by the Sons of Hodir, and spare you the very, very long rep grind (though I recommend doing the lead-in quests anyway). This was probably seen as much more balanced, and it's probably a good thing that they did that. For some classes/specs I bet you couldn't find four major glyphs that actually made a difference. Some? Sure. All of them? Heh, no. A straight stat boost is probably preferable to a random glyph that you may or may not actually use.
I have a Tauren character and like collecting mounts and would also like to get the mount achievements. With the new patch lifting the mount restriction, how do I go about getting to exalted with the other Horde factions? The only things I know of are doing low level quests and turning in runecloth. I'm only high honored or low revered with the other Horde factions and the thought of grinding out hundreds of stacks of runecloth fills me with dread.
If you don't want to churn out Runecloth or grind tons of low level quests, Alterac Valley or seasonal content are your best bets. Alterac Valley has all of those random turn-ins like armor scraps and Gnome Toes or whatever, and seasonal content seems to give a lot of reputation. There's not a whole lot for Winter Veil, but as other readers mentioned, the Lunar Festival awards a crapload of reputation if you can wait that long.
How do you not run out of titles?
Why has Blizzard added so many high elves to Theramore, Dustwallow Marsh, and most places in general?
Well, High Elves are still a major part of the Alliance, even if they don't have a capital to call their own anymore. Stormwind has always (in WoW) had a few High Elves, and there were other outposts around the world dedicated to them, though Alliance didn't quest with/around them much. The Horde mostly interacted with them via killing them. The Burning Crusade had the Allerian Stronghold, too.
The High Elves have been a pretty major force in the Alliance, they're just now getting roles on the front lines and in the spotlight, rather than pretty faces in the background.
Oh, and High Elves are totally awesome and I would pay good money to be able to play one. More please! Blood Elves just aren't the same, you know?
What's the story on Stars' Rest? Have they been there long, or did they only arrive with the rest of the invasion forces?
You can assume that most of the Horde and Alliance camps in Northrend are fairly recent. Stars Rest is probably pretty new, but it's possible it has been there for a little while already. It seems like places such as Wintergarde Keep have been there for a couple of years at least, acting as a vanguard, keeping tabs on the Scourge, things like that.
Most places like Valiance Keep seem pretty new, but Wintergarde seems to have been there for a long time already, enough that they've had to pull in common folk to keep an entire village running for the soldiers. The 7th Legion (the Alliance's Elite) is in charge of the military here, so if any branch of the Alliance military could survive in the heart of Scourge territory for a couple of years without much support, it would be them.
What that means for Stars' Rest, I have no idea.