After the bloat of subjective opinion and joy of the holidays, let's return to the mathy work that you've come to know and love from this site. Or know, at least.
On the official tanking forums I recently did a comparison between what a warrior and a druid can expect from their itemization scaling come T8. This assumes all sorts of handwaving crap that kind of sucks, and I'm not proud of it; this is basically useful for a talking point, but not all that useful for, you know, actually proving a point. But that's okay; I'm mostly speculating.
The basic idea is this: given the itemization we've seen from Naxx-10 and Naxx-25, what can we expect in terms of gains from Ulduar-level content? The methodology was as follows:
if it has a tier piece, compare the two directly. So T710 helms compared directly to T725 helms.
If it doesn't, average all the pieces in that slot and use that when it made sense.
If that doesn't make sense (like something having a TON of parry on it) convert that stat to another for easy comparison.
Both druids and warriors compared the same cloak, rings, and amulets.
I assumed a druid would be using DM:Greatness and Essence of Gossamer, and assumed there'd be a new version of both in T8. Same went for a warrior, save that they'd be using the strength version of the DM:G.
I converted hit to expertise when I could.
No gun was used in the comparison, as I figured there'd be no new thing for warriors.
The spreadsheet is over at google docs, if you want to check it out.
The results are:
Total itemization points: 429, or 326.4 for normalization of stam.
Block Rating: 44.33
Total itemization points: 684.6, or 617.6 for normalization of stam.
The warrior gets nearly double the itemization points from gear a druid gets. This is even deceptively high, as we were counting strength in for the druid as well as counting defense fully. Take those things into consideration and the value is more than double for the warrior.
This is one objective reason for the feeling that druids have a ton of 'wasted' stats. If bears are to scale at the same rate as warriors, they need to get double the value out of these stats. Currently, they really do not. What's interesting to me is that stamina for warriors and druids is basically the same, but druids scale much better with stamina. That HP gulf that druids have currently is only going to increase as gear improves. At the same time, druids are losing out heavily on the avoidance side of the equation, at least in terms of itemization, and given that the diminishing returns from miss are very small, that high defense that warriors get is going to increase the avoidance advantage they have.
Does this mean that druids are going to suck in T8? No, clearly not. This doesn't take into account any of the scaling factors that druids or warriors have, or how they improve with these stats or how good they even are. This doesn't factor time to live, survivability, mitigation rates, overall damage reduction vs types of bosses...it's very limited.
At the same time though, it does illustrate exactly how many stats are essentially wasted for a druid when they go for that rogue gear, and how much better warriors have it in that regard.
I do think that without any changes, this is going to be a problem for blizzard and for bears. Having only a few stats to scale with means those stats must scale insanely well. When that happens, it creates a very unbalancing state where weird things happen. We're already at that state now in some ways; stamina is kind of insane and it's to the point where a bear can wear polar gear and be a good tank (or even an optimal one). Giving more stamina may only exacerbate that issue. More stats that give smaller increases is a naturally more stable situation; it means that you cannot find that one broken item (right now: defender's code) and make yourself ridiculous. Diminishing returns fixes that to a degree, but that only goes so far. What I don't know is whether this is going to make bears ridiculously bad or good. But I do think that it's going to be an issue come Ulduar without a change.
That being said, GC has already said they are looking into more offensive->defensive conversions in the future. That would go a long way towards fixing issues like this.