Real Climate has an informative post on melting in Greenland and Antarctica, which seems to be higher than projected by the last IPCC report. This could add about another 15 cm (about six inches) to sea level rise by the end of the century:
[A]t the continental scale, there is a new assessment of the net mass balance of Antarctica and Greenland. Rignot et al have updated results, including those from the GRACE gravity measurement satellite, to the end of 2010 and show that the downward trend in ice mass is continuing (stronger in Greenland than in Antarctica). The net rise in sea level associated with this decline is about 1.3 mm/yr, which will likely accelerate with further warming. Complementary analyses of the surface mass balance of Greenland (Tedesco et al, 2011) also show that 2010 was a record year for melt area extent.