Full patch notes can be found here: http://forum.paradoxplaza.com/forum/showthread.php?616214-Patch-1.06-Change-Log

I will copy the major changes below:

- Muslim Decadence System

- Muslim Polygamy

- Added new provinces, titles and history for Mali, Songhay and Ghana

- Added the province of Aprutium (split off from Spoleto)

- Added the new creatable Empires of Russia, Britannia, Spain, Francia, Scandinavia, Persia and Arabia

- Strong and Weak Claim System

- Overhaul of game text for Muslims

- Added plots to claim titles

- Split up the former Kingdom of Khazaria into many de jure kingdoms

- Split the Kingdom of Rus into the kingdoms of Rus and Ruthenia

- Added the duchies of Susa and Latium

- Revised murder plots completely. No decisions, just events.

- Commander traits added

- Heavily revised combat tactics

- Loads of new events

Looks good to me!

They aren't saying what the people who buy the DLC are getting though, right? That's what I'm most wondering, because this patch is going to everyone.

@Animasta: That's a good question, it's weird for them to put the expansion's features into the patch notes, but I suspect that it might actually be common practice to add DLC-data in patches since I remember something similar being done for Bethesda games and people figuring out what the next DLC would be before any announcements from digging in data from patches.

There probably is a separate list of expansion features out there, though.

if the next DLC isn't pagan DLC than they have fucked up; my favorite game of CK2 was CK2+ suomensko duchy of estonia

@Animasta: Aren't there any good mods for that? I remember being surprised at the number of good, large mods there are for the game and they organize them quite well in the game's forums so I'd be up for taking a mod as much as I would buying DLC. The Sword of Islam DLC seemed necessary because a lot of the changes seem to be very considerate of the drastic differences between the traditions of feudal European Kingdoms and the realms of Islam.

I can see Pagan practices necessitating its own DLC, too, so you might just get one. I don't see what else they could do for an expansion.

I've spent a lot of money already this summer and I love Crusader Kings so I might just have to pick this expansion up, too.

@EquitasInvictus: well yeah, CK2+ is a mod; the best mod as far as I can tell (I am no game of thrones person, so that does nothing for me)

Is this game any good? I've only got about as far as buying it before I stopped. Pagan DLC would make me play just about anything, but I will admit to having no idea what you're talking about. :(

@Animasta: Ah I didn't notice your mention of CK2+ from your post. I just booted up my Crusader Kings II and just realized I use the same mod! It is extremely thorough and makes changes all across the board by implementing changes from several smaller ones, so I would place it as the best as well.

Now that I think of it, will the expansion be compatible with the mod or vice versa? I guess we might have a wait a little bit for the compatibility to be worked out, if not.

@mandude: If you're into games like the Total War franchise, Crusader Kings II is basically a more complex version of the grand campaign minus being able to play out battles. I think it's a fair trade-off, however, since the amount of depth and options with Grand Campaigns is pretty amazing. If you watched the quick look Dave and co. do a pretty good job going through what the game has to offer. That quick look was actually what sold the game to me and I've already put in some 30 hours in it after having it for not too long.

@EquitasInvictus: I think wiz has said that he'd be basing all future versions on DLC like this I think.

The reason the next Game of Thrones mod update is delayed is due to waiting for this patch and making it compatible, im sure thats the same deal for CK2+. The CK2+ creator (Wiz) is really active on the somethingawful thread and seems a pretty dedicated guy so im pretty confident it will turn out ok.

Apparently there might be some issues with previous save files being compatible with Sword of Islam though

@Animasta: Guess I now have incentive to pick up the DLC, then!

@Vequeth: I guess now is the time to start planning my next game!

I wonder if Dave is willing to try it out again. I really wish he was able to get a multiplayer game set up live, that might have been interesting to watch and I've wanted to see the multiplayer in action.

Ze patch is out, can find it here (50mb) http://www.paradoxplaza.com/in-game/ck2/CK2_1_06_patch.exe
 
This link is for people who have stuff like Gamersgate versions, I think steam needs to update itself.

Is the expansion out too? I'm not sure if I should pick it up now or wait until CK2+ is compatible!

Yeah the expansion is out on gamersgate and steam. 
 
Regarding CK2+: 
 

Also on the note of 1.06, I will be getting to work on a compatible version later today. Expect it sometime this week.

Apparently it came out with some new murder plots: http://i.imgur.com/T66wm.jpg