Why buy the expansion?

Burning Crusade FAQ::

There will be many aspects of the expansion that are available to all players. However, in order to experience certain content, such as the Outlands, or be able to play as one of the new races, players will have to purchase the expansion.

Fangtooth says:

I believe the level cap being raised will apply to all players, not just those who have purchased and installed the expansion.

With an increased level cap comes the new skills and abilities as well, add to this that weather effects will be in a live patch, hero classes will be in a live patch, enchanting oils to sell enchantments on the auction house will be in a live patch, housing looks like it will be in a live patch, cross-server battlegrounds might be in a live patch... the list goes on.

How big is the Outlands, really? That will determine a lot.

I know Blizzard hasn't revealed that much yet, I know. And I know I'm being shortsighted, but this is just a thought.