I hadn't heard any one else say this, but I had wondered about the heating / cooling issue at the bottom of the screen. I don't use it with a monitor. I use it as a regular laptop. The bar though still is warm to the touch. I also only waited to clean the screen after the macbook had been turned off and had a chance to cool, which is what the FAQ section of their website recommends.
When I saw the new Macbook Pro, with the aluminium hinge I wondered if this is one of the reasons it was swapped from plastic.
Ok. Sounds like it is not the issue for you.
I was using mine rather heavily yesterday just before leaving the office. I had it training a deep network which caused the CPUs to run all the cores (15" quad) wide open for 15-20 minutes. When I started packing up I noticed the screen was really warm at the bottom. It did not burn when touched, but it was hot enough to make you pull your hand away quickly.
And I even elevate the unit on a 1/2 thick book to get more air to the intakes on the side and allow more open area at the rear exhaust.