Progression will be: normal dungeons - HC dungeons - Normal raids - Heroic raids
the gear we can buy with the lower value points will only net us blue gear that's good enough for entering heroic dungeons.
Also, the gear and lockouts will be shared by 10 and 25 man raids.

... I can't think of any other pertinent info for raid progression.

It seems likely that major content patches (4.1, 4.2, etc) will take some parts out of the progression, similar to 3.3 (and to a lesser extent, 3.2) did. You'll still build up gear by normal/heroic/normal/heroic (dungeons then raids), but in 4.1, for example, you won't have to progress all the way through BoT/TFW/BD to get to whatever new raid is in 4.1 (I'm theorizing on either Firelands, Emerald Dream, or Nashjatar). New toons will play catch up in new dungeons in 4.1, which will drop similar gear as previous-tier raids, much like ToC5 and ICC5.

I'm guessing the item level progression will be (4.0/4.1/4.2/etc respectively)
Normal 5: 333/346/359...
Heroic 5, Justice: 346/359/372...
Normal 10/25, Valor: 359/372/389...
Heroic 10/25: 372/389/402...

Oh, I should clarify, that updated item levels in those difficulties refer to new dungeons/raids introduced in that patch, any existing content will not be upgraded to match.

Yes, Blizzard is immensely proud of their strategy in WotLK.

In Vanilla and BC, it was generally problematic if you had an alt, or were a player who did not start playing at the start of the expansion, and if you got behind and missed the first tier, you would generally find it impossible to catch back up and see the final dungeon.

Blizzard felt this was a bad thing, and from now on, you can more or less go straight to the current raid content as soon as hitting 80, no matter which tier they are on.

(To some extent, this almost seems to make the concept of tiers a little silly :P)

@Hanak's:
"the gear we can buy with the lower value points will only net us blue gear that's good enough for entering heroic dungeons."

That should be: "only net us blue gear that's as good as the drops from heroic dungeons."

Yaaargh justice points will allow us to purchase heroic dungeon level blues and valor points for first tier raiding level gear *initially* however when the second tier of raiding comes out all your valor points will be converted to justice points, and first tier raiding level gear will be changed to cost justice points to make way for the second tier raiding level gear which will now cost valor points! It will be just like it is now, except simplified to use only 2 types of currency rather than having one for every raiding tier with the lower ones gradually becoming obsolete.

So yes, you'll still be able to enter whatever the latest tier of raiding is by farming heroics.