There has been a fair amount of earthquake activity in the vicinity of Puerto Rico and the Dominican Republic in the last few days, with the largest at magnitude 4.1 (near Monte Plata, Dominican Republic), and more than a dozen at greater than magnitude 3. These quakes are happening several hundred miles east of Haiti, which was struck by the horrific quake in January.
Earthquake swarms like this are not unusual, and probably don't signify a threat of greater quakes to come. We have swarms in California constantly, but they quiet down, and nothing comes of it. If anything, though, the quakes should be a reminder that Haiti is not the only Caribbean Island to experience serious earthquakes. Puerto Rico has a "rich" history of earthquakes, with magnitude 7+ events in 1670, 1787, 1831, 1844, 1846, 1865, 1867, 1875, 1890, 1906, 1918, 1943 and 1946. Science Daily has a good rundown on the geologic environment and associated earthquake risk in the region.
Thanks to Edie for the tip!