I recently bought the baseline 13'' Macbook Pro with i5 CPU and Lion preinstalled.
I mostly work with Firefox (without Flash), NetBeans IDE and iTerm running and the machine tends to get really hot at the bottom and in the upper left area of the keyboard after few hours of work.
I checked the Activity Monitor and no process is above the 5% CPU usage.
My friend who has the same MBP with Snow Leopard started to have the same issue after he upgraded to Lion yesterday. Lots of threads on Apple.com support forums report the same issue, but without any working solution.
What should I do? Should I bring it back to the shop? Should I try to take some steps to prevent the overheating?