Update: The 520 - 1200 metre wide asteroid 2010 TV149 made a close pass (53.4 lunar distances, 0.1372 AU), travelling at 10.89 km/second, to the Earth-Moon system on the 21st December, 2010 @ 18:31 UT.
The 500 - 1100 metre wide asteroid 2010 TV149 will make a close pass (51.1 lunar distances, 0.1312 AU), travelling at 10.73 km/second, to the Earth-Moon system on the 20th December, 2010 @ 03:08 UT.