The webcast of the release of the Philae lander from the Rosetta spacecraft has begun: Rosetta | rendezvous with a comet.
The actual separation and landing will not happen till tomorrow (Nov.12):
Separation of the lander is planned for about 09:03 GMT (10:03 CET) [4:03 am EDT], and touch down should follow about seven hours later, at 16:02 GMT (17:02 CET) [11:02 am EDT].
See also latest info at:
Here’s the Rosetta and Philae landing timeline – Rosetta blog:
Here is a video about the challenges of landing on this comet: