Facebook often uses their sidebar to promote other products and features:- Image labeling - The friend finder tool - Facebook job openings ... etc Today was the first time I spotted integration of Facebook Places - specifically with "recent checkins". The unit shows checkins by your Facebook friends with timestamps and links to the locations / hubs.
I personally hope that this is the beginning of a larger location feed / map... interestingly you will notice that there is not a 'see more' link. Hopefully that is to come.