Blizzard's months of nearly complete silence on the forthcoming expansion was explained yesterday as they unleashed a mammoth media event designed to garner the front page of every major internet gaming outlet out there. This was pretty successful.
In my opinion, the two biggest issues in TBC were the inaccessibility of major lore events and the lack of progression past a certain point for players who do not raid. I've discussed the gear issue into the ground here on this blog (notably here and here), but this is probably the first I've mentioned the lore issue. As an expansion, TBC has a single, main plot that hits you from the moment you pop the CD into the drive and watch the opening cinematic - Illidan and his minions are doing terrible terrible things, and must be stopped. Where the original WoW features many storylines (only some of which actually dead-end in raids - though some simply dropped off the face of Azeroth only to come back 3 years later), TBC is all Illidan, all the time. Everyone experiences that story, and knows WHY Illidan must be stopped, but only a small fraction of players will ever actually get to see the big finale (the story sequences during the Illidan, and apparently Kil'Jaeden, encounters), as these are limited to 25-man raids. It's like buying a book and turning the page to discover that the final chapter will only be available to you if you join a 25-man book club that meets at fixed hours, requires preparation work before mettings, and generally forces members to completely change the way they read.
Well, the info blitz suggests that Blizzard is taking a swing at both problems in one fell swoop. Every single raid zone, including Arthas' lair in Icecrown Glacier, will be available in 10 and 25-man flavors. Don't get me wrong, I'm still not going to get to see the Arthas fight unless I'm able to pay someone to take me there (which might be possible if the fight isn't tuned so hard that it cannot be beaten with a single under-geared/coordinated player), but it's certainly a step in the right direction.
In discussion of PVP rewards, Blizzard implies that there will ALSO be an implementation of tiered progression below the 25-man raid level. The example they use is for PVP rewards, where they suggest that the top end, high rating arena gear would be on par with the current 25-man raid gear, the low end, low rating arena gear would be on par with the current 10-man raid, and the no-rating-required honor gear would be on par with heroic 5-mans. Of course, that's not much in the way of details, and they don't say whether they will extend the concept of continuing progression all the way down to solo/daily content (though they seem to be very aware that this demographic pays a fair chunk of their bills). But it's certainly a start.
There's a lot of other interesting tidbits of info out there, but details are scarce and subject to change, so I'll refrain from making comments/predictions/analysis that will likely be proved wrong down the line. But, where the big picture is concerned, it sounds to me like Blizzard hasn't missed the point the way they did with TBC at its launch (where their response to complaints that raiding wasn't a gameplay style that people liked was smaller raids).