Tax disadvantages for becoming a realtor?

[JD Martin]

Hi all! 

My agent keeps encouraging me to get my real estate license and work under his brokerage. I have some interest in this as I might like to go full blown on property management in a couple of years (you need 3 years agent here before you get your brokers). What I'm trying to figure out is if there are any tax *disadvantages* for becoming a realtor if you already own a bunch of rental property?

Currently I file just a regular 1040 with the requisite Schedule E's for the properties. I certainly wouldn't want to do anything that might negatively affect my filing abilities. He tells me that there's some pretty significant benefits for getting my license, but I have to preface that with the fact that I have a regular W2 and am not going to work anywhere near a full-time gig as a realtor; I'd be surprised if I had more than 100 hours in a year in it total. And of course there's some costs to getting my license.

I'm interested in hearing from some of you that may have went from rental property owners to realtor, and what you might have saw. Also from some of our tax-savvy people around here!

@Natalie Kolodij @Brandon Hall @Linda Weygant