This show looks like it could be good; it has a wonderful premise involving a Hyper-observant protagonist with conflict seeking attitudes. i believe that if your a fan of shows like House, Psych, or even (sigh) The Mentalist, you know that this scenario is full of not only vary amusing, but also highly thought provoking potential material.
shows like this are different from normal 'detective' or 'mystery' shows because of the protagonist. 'he' is special in the manor in-witch his observation and deductive reasoning works (its almost like fast forwarding), and he uses it to his advantage. combined with his slightly abrasive attitude and his almost chivalric moral code; you can tell that there are going to be moments where he just slams characters who are jerks by completely calling them out, and thats ALWAYS fun to watch. oh, and the accent, gotta love that.
really the only negative thing i have to say is that due to this wonderful scenario, the show will be forced to give the audience ridiculous amounts of information (i.e. those micro-freeze frames on expressions, the zooming in on important lines/lies) which in turn runs the risk of having predictable plots.
i feel the risk is grater in this show then the others i mentioned because, well, for instance in House, a huge aspect of the plot is in a specialization in medicine, without possession of such knowledge, the show also takes on a sense of mystery, not to mention the plot-twist opportunities provided by medical catastrophe. Lie to Me doesn't have that exclusive knowledge. as the show mentioned, expressions (and sadly lies) are universal, so all possible audience members have experience with and can relate to the material that is the main focus of the show (both good and bad really).
on top of that i also find that unless they model the show (loosely) on actual events, that is to say actual cases that have the involvement of hyper-observant/expertly trained people (granted, there are few) and then shape the events to match the characters/attitudes of the show- it runs the risk of having more or less predictable drama that is the downfall of so many potentially great shows.