According to the ESA Rosetta webpage:
http://www.esa.int/esaMI/Rosetta/SEMC20VOM8F_0.html
The probe will be at closest approach on the 13th Nov. 2007 at 21:57 CET which translates to UT +1, which for us here in the west with the horrible daylight savings means 05:57 WDST on the morning of the 14th (I think? If I've got the maths right.)
Rosetta will at this time be 5301 km above the Pacific Ocean SW of Chile at 63° 46' south and 74° 35' west, travelling at 45 000 km/hr.
According to StarryNight pro the probe will be mag. 12.72 in the northern sector. See attachments. (these screenshots are for 22:30hrs WDST)
Could be quite a challenge!!