Update 28.10.2008:
Couple of other important notes:

• The scourge invasion will continue for a few more days.
• The prologue event is not over! More to come!!
• The Karazhan boss will be up for approximately another week still
• We increased the respawn rate of the Necropoli
• Zombie cure should kick in by around noon PST

Update 27.10.2008: (Phase 5-5.)
The infection is still 1 minute. New npcs have arrived with quest in Shattrath

Update 27.10.2008: (Phase 5.)
The infection is now reduced to 1 minutes. Most Argent Dawn healers have left.

Update 26.10.2008: (Phase 4.)
The infection is now reduced to 2 minutes. There are necropolis all over Azeroth and a new boss in Karazhan.

According to reports from around Azeroth, infected crates can now be found in some major cities. Other reports inform us of Infected Roaches spreading the disease if you kill them. Looking at the 3.02 patch notes and the main header image we can only imagen what will happen at a later stage.

Found in the rotting diary of Eric Farrington in the dead city of Andorhal…

Wednesday
My beloved home, Andorhal, has fallen victim to an evil plague. I have witnessed the horrors of the Scourge firsthand, and seen unimaginable things. Death was not granted to my loved ones. Instead, everyone I’ve ever known has turned into monsters. Monsters of unfathomable, relentless viciousness!

I thought naught of a few illnesses, a few fevers. We continued to ship out crates of grain to Lordaeron, and we weren’t fearful of this new sickness — we were confident our healers could handle it. I know now that was foolish, blind.

The denizens of Andorhal turned into vile zombies of the Scourge. These monstrosities no longer held any thoughts or abilities from their mortal lives. Most certain of all, they readily used new powers we had never seen before to further spread the disease and hasten the destruction of the city.

I have been hiding for two days in the sewers, but I must venture out soon to find supplies or possibly a way out of the city to the forests.

Friday
Help me, I’ve been bitten!

I cannot believe I was foolish enough to think I could sneak past all of them on the streets. The zombies are everywhere now, and Andorhal is only a shell of its former glory, a sad and twisted remnant of my beautiful home.

I can already feel the disease taking me. May the light bless me as I go to be with my family and friends once again. I’m not sure how much longer I can keep my sanity. I am weak. I hunger, and must eat…

Eat…

Brains…

The Scourge Invasion is upon us! Prepare yourself for the deadly onslaught of the Scourge, unleashed upon Azeroth and all its denizens.

Source

All players will have their talent points reimbursed and will have access to new talents throughout their trees; this includes the 51-point talents. Several new spells and abilities have been added for all classes. Players will need to visit their class trainer to learn new spells

Source

Cold Weather Flying was indeed a part of a quest line, but we changed it because we felt that it wasn’t clear enough where to get it.

This ability will now be purchasable instead, and the 1000 gold cost has been tuned around the amount of gold people will usually have gathered around level 77. At that level we expect you will have more than enough gold to afford getting the Cold Weather Flying ability.

We had hoped that the introduction of some new Honor rewards in the upcoming patch would give players a great opportunity to spend any of their remaining Honor. However, many players would still be surprised by an Honor and token reset as it isn’t something we’ve done in the past. As such, we’ve decided to not reset Honor or tokens upon the release of Wrath of the Lich King. Players who save their Honor will be able to spend it on level 80 rewards, although those rewards will be significantly more expensive than their level 70 counterparts.

Source