First a little bit of perspective in my life. I received an early beta key due to having signed up for the yearly pass. With that, the new mount they offered (shiny pegasus) and the free copy of Diablo 3 it was an offer I couldn't pass up. I have logged onto the beta servers at some points in the past few months to check out the feel of the panda invasion.
Anyone who has played on the beta servers will tell you that the economy tends to be very wonky. Everyone has a large amount of gold from the start, and gear is overpriced. You do not have the same amount of raw minerals that you do on a live server, and nary a Chinese gold farmer is seen.
What you do get is a good idea of the upcoming professions when they roll out. How quickly there is in rising to maximum level the professions. And just how difficult certain areas will be for farming. It's a good chance to plot out the future runs that will be necessary to get to the higher profit margins.
But here is the big secret. There are always people that are smarter than you and have more time spending hours on the beta servers, picking up every little bit of information that is available. This isn't a question of your intelligence, because I would like to think that if your reading this your in the 1% of gold making intelligent players. What it does say is that if gold making is your primary interest then searching for snippets of information on websites can be more fruitful than trying to dig up the information yourself.
We know that the UI addons will be available with the next patch for the beta servers. This will give addon programmers their first chance to tweak their code for the expansion. It will also allow players to see if they need to change their UI to something more useful.
Mists like every expansion will change how we play the game. With the new class and profession changes becoming available, gold goblins will have to adjust both to be at the top of the markets.
Good Luck and Good Hunting