In indoor sections and outdoor sections during night, yes. Outdoor sections during the day, no. I was in Nellis Air Force Base during the day time and the game would hang for several seconds at times, it happened a couple times after quicksaving. Also that log ended on a CTD.
My specs:-
Intel Core 2 Duo E8500@stock speed, 4GB DDR2-1066, Nvidia GTX275 896MB@stock speed, 7200RPM SATA2 HDD. Win Vista x64 SP2.
Game on max graphical settings, 1680x1050 resolution, NMC high resolution textures installed. Some memory allocation and multi-threading tweaks applied to fallout_default.ini based upon http://www.tweakguides.com/Fallout3_10.html.