In the article this weekend So Few Properties, So Many Brokers [NYT]  Nadine Broznan paints an accurate but bleek picture from real estate brokers entering the profession today. After several years of boom times, the future is less certain.
The Real Deal did one of its usual exhaustive surveys on brokers and agents [pdf]  finding that in the top Manhattan ten real estate firms, 30% to 63% of their brokers had no listings.
For the most part, people entering the brokerage profession have missed the boom [Propery Grunt] , no matter what happens to housing prices. There simply appears to be an oversupply of agents [Matrix]. 
For brokerage firms, it provides an opportunity to upgrade existing staff since every new agent creates additional overhead costs that has to be accounted for somewhere.