From the ARRL:

On Tuesday (January 12) there was a 7.0 magnitude earthquake in Haiti , which has since been followed by serious aftershocks.  Communications in and out of Haiti have been disrupted.  No word has been received as of yet from any of the national HH Amateur Radio operators.  The DailyDX notes that HH2/HB9AMO, Pierre , is OK and was located about 140 km north of Port-au-Prince in Cap Haitien at the time.

The IARU Region II Area C Emergency Coordinator, Arnie Coro, CO2KK, is coordinating the multi-national response by hams.  There are organized nets on 7045 and 3720 kHz and amateurs are asked to monitor but also keep the frequencies clear of non-essential traffic.  Amateur Radio operators should also be aware that emergency traffic pertaining to the Haitian earthquake is expected on the SATERN frequencies of 14265, 7265 and 3977 according to SATERN’s leader, Major Pat McPherson. The Salvation Army has a website up for H&W traffic and other news at www.satern.org.

Amateur Radio operators are circled around Haiti in Cuba , Florida , the Dominican Republic , Puerto Rico , Venezuela and other locations listening for any calls, but   so far no HH stations had checked in.

Please keep clear of frequencies :

14265
7045
7265
3977
3720

The situation is still chaotic and more information will be posted as soon as possible.  Information is being validated and shared between many amateur groups and news sources as it unfolds.