The latest online chatter indicates that Olympus may release a new version of their m4/3 camera line in the next 1-2 months. I do not have any further details, but the new PEN model could potentially be called E-PL2.
The PMI 2011 show this year will take place in September (the show is usually held in February) and camera manufacturers may still make their announcements in February even without an actual show.
The other possibility is CES 2011 (January 6-9th, 2011). In the past, CES is usually the place to announce consumer cameras but this however, may change in 2011 since PMI is still nine months away.
FYI: in November of 2010 Olympus announced the E-PL1s which will be available only in Japan. Olympus E-PL1 was announced back in February during the PMA 2010 show. A black version of the E-P2 was announced in August of 2010.