Well, it's official - GC has gone out and said that Titanguard won't be making it in, and explained why.
What this does for druids: not a lot. It would've been another nice source of stamina for Sarth3D, but for normal tanking duties you'd still want mongoose. Having options is nice, though, and I was really looking forward to having a stam stick and an avoidance stick. Ah well.
What this does for paladins/warriors: OMG END OF THE WORLD AAAAAAH. Or, ya know, not. It's true - there just aren't any particularly sexy enchants on weapons right now. Mongoose for warriors and paladins is pretty subpar given the typical fast attack speed for them. The exception would be if they're using Broken Promise for some reason; if they do that, mongoose should proc about the same for a warrior that it does for a druid. (Paladins are still screwed, as most of their threat-generating attacks aren't weapon based). At the same time though, what options do they really have? Yes, 75 stamina or 50 stamina would've been the best for them, but at the same time 50 stamina really isn't that much on the grand scheme of things. Compare this to 63 spellpower or berserker, and it's just seemingly really arbitrary that tanks can't get anything of this nature.
What I'd like to see: a 50 stamina enchant that costs roughly the same mats as 50 spellpower does. Then a better tanking enchant that doesn't give stamina but does give some kind of mitigation ability based on damage dealt. It should not have a proc mechanic; that screws over the fast-hitting attack method of the warrior and the lack of physical attacks of the paladin. Ideally it'd have an internal cooldown but a high proc chance, so that the overall uptime is consistent and it can give the tank some control. Let that be the one that costs mats similar to Berserking or Black Magic. Make it only slightly more powerful than the 50 stamina enchant, but definitely make it work out that it's more powerful overall. This isn't that hard; 50 stamina doesn't win out all the time, and depending on the enchant could be much better for some fights and worse for others. For instance, on the wow forums I recommended an enchant that occasionally creates a spell reflect shield with 3 charges; if the spell could not be reflected, it would be reduced in damage by a certain static amount. This wouldn't be great against Patchwerk but would rock on Malygos and Sarth - and it'd be great for druids and paladins, who don't have as many anti-magic alternatives. But would you use it all the time? Probably not.
With all of that being said, tanks aren't exactly crying out for a new enchant to their weapon because they can't do the content. They're just bored with using BC-level enchants on their new shinies. I can appreciate that too; it's kind of lame hunting down the couple of people still around with mongoose to go log in to their alt and make it for me every time I get something new. My gut feeling is that they didn't want to do Titanguard because they've already very tightly tuned Ulduar around expected stam values for tanks, and giving them more would make it that much easier. We'll see, but it's hard not to be disappointed that there still is no tanking-specific enchant at any real level other than a weapon chain.