It really depends on the state, but more and more states are requiring Loan Officers (LOs) to become licensed. The procedures involved in the licensing process are dependent on the individual state. In certain states, like Iowa or Nevada, someone applying for a loan officer's license needs to complete an exam and have a full background check completed before being granted a license. In others states like Florida, there is no licensing at all, and the brokerage owner is the only one that is required to go through a background check and testing. 

The mortgage meltdown has really shed light on how little regulation there is in the mortgage business. Much of the reason why so many poor loan decisions were made results from the lack of accountability and personal responsibility that was placed on the individual LO. 

Within this decade, it wouldn't be surprising to see federally-mandated testing being required, similar to the type administered to stock brokers.

For a list of Loan Officer and Broker requirements in your state check out of State Licensing Section.