For everyone who is ashamed as buying a mount, don't be. For everyone who is mad about blizzard selling them, go for it.

This is the nature of a free market system. Blizzard obviously would not have made this horse if they did not think there was a demand for it. Blizzard is going to do what's best for their bottom line. They want more money, so they sell a celestial steed. It's a win for Blizzard, and a win for whoever wants to buy the steed.

Whether they move on to selling other items is a bigger decision, one of "can selling items in game make up for the loss of money from cancelled subscriptions?" If there is more money in selling items in a virtual store, then obviously that is what Blizzard should do. But something tells me that alot of people would not find this attractive, and that is why Blizzard has not done it yet.

Blizzard is out to make money, not screw over people. You may feel like Blizzard is turning the game into one of those crappy free internet games where being geared means buying lots of items from an online store, and that is completely justified. But telling other people their idiots and condemning them for how they spend their money is very judgmental and irrational. Imagine a world where everyone bought the exact same things you did and nothing else.

So here are your options:
1) Buy the mount (you obviously want it; it's not being forced upon you. If you buy this mount, there's probably a good chance Blizzard will make more cool vanity goods, which is what you want. By buying this good, you are essentially telling Blizzard that you approve; you vote in favor of the steed and/or selling virtual items. This basically tells Blizzard that there is a market for this type of good, and that money is to be earned. While they are making money, you are provided with many more new vanity goods. So it's a win-win for Blizzard, they get money, and the consumer, you get cool new things).

2) Don't buy the mount (you don't like the mount, so you don't buy it. It's as simple as that. Blizzard can interpret this as a "no-vote" for either the mount and/or selling virtual goods. I am not going to buy the mount because I don't want to spend the money on the steed specifically. This doesn't mean that Blizzard is ignoring me, but rather that I am just in the minority of consumers.)

3. Quit playing WoW (you think selling this steed is the last straw when it comes to selling virtual goods, and nothing gets you more angry than those games with virtual stores. The choice here is very simple. If you do not like the product, then don't buy it. Remember, Blizzard is out to make money. If you quit, they are no longer getting your money. Therefore, if the majority of players do not want this type of system, which I suspect is true, Blizzard will not implement it, because they would lose lots of money. When you quit, you are basically telling Blizzard that you do not like their product. If the majority of people quit due to the creation of a virtual store, what would Blizzard do? They would obviously stop the virtual store because it has fallen out of favor with the majority of players in the market for MMOs, and Blizzard as a corporation would want to remain competitive in order to make the most money.)

What to take from this post: Blizzard wants money. In order to make the most money, Blizzard will follow the majority of players. If you think selling goods in a virtual store is wrong, then don't pay for Blizzard's product (noone is forcing you to buy it).

Ultimately, if you like it, that's great and you are probably with the majority of players. And if you don't like it, then that's fine too, I outlined your choices. The anger you're feeling is one of powerlessness; you feel that Blizzard is not listening to you even though you pay for their bills. Really Blizzard is listening to you, but you're just in the minority of players. It's like the old saying, "democracy works great, but only if my side wins."