Imagery from the recently-launched Landsat 8 are now updating weekly in RapidIce Viewer. As with Landsat 7, RISCO provides 15-m panchromatic (band 8) imagery from the Operational Land Imagery (OLI). These data are distributed by the U.S. Geological Survey and are available over Greenland starting in early April. We antcipate the first Antarctic images beginning in late August.
One difference from previous imagery is that Landsat 8 is distributed as 16, rather than 8, bit imagery due to the high radiometric precision of these data. Be aware that some software may have trouble reading 16 bit imagery.
You can read more about Landsat 8 here: http://landsat.usgs.gov/LDCM_Landsat8.php