Just thought I'd break some of this down to show the other perspective...
Why has there been no sort of visual improvement to the original races yet?
This one, I don't know. I'd assume it's a low priority thing. I know some of the developers have expressed interest in doing it in the future.
Why is there still no form of housing in the game?
Too impractical. Where would you git everyone's house? Or even just houses for guilds?
Why can't you name warlock pets?
This is intentional. The concept is you are just summoning and forming a contract with an already living, intelligent being. It has it's own name.
Why can't you change the color or at least choose the model of pets?
You can tame the colour you want. There are generally 2-3 per pet available.
Why are most mounts and armors simple re-colorings of old armors and mounts?
This is a fair complaint. But has gotten a LOT better with Cata and the most recent patch.
Why is there such limited music in the game?
Can't comment. I turn my down to hear in voice chat or play my own music. But I hear this is also better with Cata.
No dyes? No new hairstyles?
There are new hairstyles. But they can only be accessed from the barbershop. There is no real need for dyes. There are enough available colours.
But I do understand where you're coming from.