Gus has been running just east of the NHC line, this might be a result of his impressive spin up or a weakness in the high to the north... or most likely a combination of both. Looking over the water vapor loop I see the front in the eastern US is sliding out of the way which would allow Gus to continue this NNW motion, but the next front coming across the central US doesn't seem very strong (or very deep) so he can curve back west easily. This would explain the NHC straight-as-an-arrow forecast... there is nothing major that would greatly influence Gustav's movement in the GOM so its steady on the course for the next few days.

I still feel the storm will make landfall closer to the LA/TX border late Monday/early Tues AM, as the only weakness in the atmosphere seems to be over TX right now. Unfortunately this turn to the west will only make the surge worst as more of Gustavs's winds push up against LA. This puts New Orleans on the "dirty" side of the storm which would be very bad for them, even worst then last time I fear

However based on all the news reports it looks like everyone learned their lesson and are getting out of harms way.