One issue with focus though is how new raiders will learn the ropes. It used to be that older learning instances were still in the rotation (so you'd join a guild which ran them). If people are coming straight in to the latest raid, where do the learning instances fit in?
I am beginning to wonder if new raiders actually need learning instances. I think that on the institutional, or guild level, learning instances are important. But for an individual raider, it seems like individual raiders can learn quickly when integrated into an already experienced group.
Yeah, they don't know the tricks and shortcuts. You can't go "This boss is like Chromaggus crossed with Illidari Council". But individuals not having done the learning instances doesn't seem to have significantly hurt, at least in my experience. It's actually kind of shocking to go into Ulduar with someone you think is an extremely experienced raider, and she starts picking up the basic achievements.
This is just the individual level, though, and on Normal modes. Exposure to the experienced group seems more important than exposure to previous content. However, I'm not sure throwing a group of people who have never raided before into ICC will really work.
There are middle ways like: standard progression but every month all existing raids get a 5% ICC-like buff. So imagine the old MC-BWL-AQ40-Naxx way, but one year after start MC has a +60% heal, HP, damage buff and BWL has +30%.
I think this kind of cuts against the whole progression idea. The idea is that every group encounters content in more or less the same difficulty. I really don't see any difference between getting i251 gear and going back a tier vs a 60% buff.
If there's going to be a 60% buff, why bother making them do the old content at all? May as well just point them to the current content content and tell them to have at it.
I don't understand how the WotLK raiding system helps people see more content by skipping to the last raid of the cycle.
In both styles, you are not seeing content. So I don't understand at all how that somehow becomes a part of equation.
The difference is in Wrath, you don't do earlier content by choice. Your ICC guild can always go back and run through Naxx and Ulduar for fun. Odds are you'd be able to complete it fairly easily. My own guild did Yogg+1, Yogg+0, and got someone a Valy'nar at the end of the expansion.
In Vanilla/TBC, the upstream content was pretty much blocked. Once a guild was stuck, it was stuck. There was no aspect of choice involved at all.
If MC was dropping 6 items per boss instead of 3 when AQ40 came out, new players and less progressed guilds would have been able to catch up faster without getting a free skip-all-old-content pass.
I don't think I agree with this. In my experience, by the time your guild reaches a boss, you have enough loot to beat that boss (excluding edge cases with the Royalty guilds). Loot is very rarely the true stalling factor.
Now, you can use loot to overpower fight, but that generally requires loot from higher tiers. The current tier of loot is almost never enough. If you are stuck on a boss in a progression-style, the kill usually comes through improved execution or an improved strategy.
Do Hard Modes change things?
One thing to consider is that Vanilla/TBC didn't have hard modes. It's quite possible that the guild-killer bosses we all know and love would really be a Hard Mode in the Wrath environment. Perhaps the Normal mode progression chain would be enough to keep guilds from stalling out.
Obviously a lot of the Aristocracy and Gentry guilds would leave Hard Modes unfinished when the next tier came out. And a new guild would probably ignore Hard Modes altogether until it got caught up. They would do Naxx-normal, Ulduar-normal, TotC-normal, and ICC-normal. There really isn't a Vael or a Vashj in that path to really get stuck on.
Other issues and thoughts
But that doesn't solve the recruitment issue. For a guild in the ICC tier, being able to recruit relatively new 80s is a huge boon. It makes life a lot easier than poaching from the TotC or Ulduar guilds would be. But if progression is in place, if you need to do TotC before ICC, then obviously an ICC guild must recruit someone in a TotC guild, or run old content to gear them up.
Maybe a different change would help. What if, when TotC came out, Naxx gear was automatically upgraded to Ulduar ilevel? And when ICC came out, Naxx and Ulduar gear was upgraded to TotC level? This would mean that Naxx and Ulduar are not entirely obsoleted. But perhaps Naxx would become the zone of choice, because it is easier than the other two but would provide the same reward.