As on the PTR, characters on the beta copy over without most of their achievement history, and it's a little weird to see yourself toting around stuff like the Loremaster achievement without actually having its prerequisites. Anyway, keep in mind that this is a snapshot of what we know in beta build 12803, and I don't believe that Blizzard's added most of the Cataclysm-related achievements yet.
I get this more than any other question. Loremaster is still very much in the game, but Ghostcrawler (lead systems designer) has confirmed that the number of quests required for it will change. Whether this will occur in the Cataclysm content patch or on release, I don't know, but my advice would be to do Loremaster sooner rather than later so you're not caught short.
For anyone who would prefer to do Loremaster in Cataclysm, zone-by-zone organization in the old world is much better. As you can see from the picture above, the developers have added the number of quests required per zone, although some of the numbers are temporary. For example, the Ghostlands, Searing Gorge, Felwood, Silithus, Thousand Needles, Winterspring and Hillsbrad Foothills are all listed as requiring 1,000 quests for their respective zone achievements. If you check Blizzard's Cataclysm zone status page, you'll note that each of these zones is still slotted for an overhaul.
Are the mounts from Wrath raiding achievements going to disappear?
Your guess is as good as mine, but for the moment, they're still there. Blizzard has said previously that it regretted removing the Black Proto-Drake and Plagued Proto-Drake from the game when patch 3.1 hit, but I don't know whether the reluctance to axe the rest of the Wrath mounts from outdated content will survive the transition to Cataclysm. As far as I know, Blizzard also hasn't commented on this yet. So, as with Loremaster, you may want to plan on getting the Ulduar proto-drakes, ToC ground mounts and ICC frostwyrms sooner rather than later.
Are any existing achievements now Feats of Strength?
As of now, no. If this does change, my guess would be that the aforementioned Wrath raiding mounts would be among the likeliest candidates to be retired and thus become feats.
New feats have been added for assisting in the invasion of Gnomeregan/retaking of the Echo Isles, but these will be in the Cataclysm content patch rather than the expansion itself. Tripping the Rifts has also been added, but again, this is likely to be a limited-time-only deal in the content patch.
Has the number of quests required for The Seeker been increased?
Nope, it still requires 3,000.
Has The Diplomat changed?
Nope. The existing achievements are still there, although a furbolg tribe named the Blackmaw has taken over the Azshara region where a bunch of Timbermaw used to hang out (and that tunnel doesn't go anywhere). The other Timbermaw (at the Felwood/Moonglade/Winterspring border) are still there and providing friendly passage to anyone who's done a bit of work on their behalf (not that it matters now that you can fly over the mountains).
Are there any new holiday achievements?
Not that I can see, nor are there any changes to existing achievements. I'm pretty sure that What A Long, Strange Trip It's Been will survive without any serious changes.
Do any achievements provide clues to new content?
Not as many as you might think, because I doubt Blizzard's added a lot to the achievements panel yet, but there are a few:
- The First Rule of Ring of Blood is You Don't Talk About Ring of Blood: We should be seeing another deathmatch-type quest or quest series in the Twilight Highlands. I've been to the zone, and while very beautiful, none of the quests seem to be there yet.
- Glory of the Cataclysm Hero is significantly less involved than its Wrath counterpart. This is either because a bunch of additional achievements related to the dungeons haven't yet been added, or it's a tacit acknowledgment that Cataclysm heroics will be much harder. As someone who has tanked and/or healed Blackrock Depths, Throne of the Tides and part of Stonecore so far, I can definitely tell you that even their normal versions are not pushovers.
- There are only a smattering of archaeology achievements so far, but they all look interesting. Blizzard could have some sadistic fun with this if it really wanted. One could start out as an adjunct professor with nearby NPCs programmed to /spit while you pass, and if the pinnacle of archaeology advancement isn't a promotion to department secretary, I will be disappointed. All you academics and former academics out there are nodding your heads right now ... or crying.
- Reputation achievements have been added for the Guardians of Hyjal, Therazane, Dragonmaw Clan (if you're Horde), Wildhammer Clan (if you're Alliance) and Ramkahen.
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