No catch, assuming of course this is your primary residence and not an investment property. Also has some legal benefits as mentioned by Arebelspy. I believe you've missed the deadline to get the benefit on this year's RE taxes, but get it set up to take advantage of free money going forward.
Another minor side benefit is the future buyer of your house will automatically get the benefit for the year they purchase your house, regardless if they're an investor. I just bought a rental property and - since it was homesteaded as of Jan 1, 2012 by the seller - I'll get the exemption for this one (and only) year.
I mention this primarily because you may receive the exemption this year if the previous owner had it homesteaded, but you'll need to file to gain the exemption going forward.