The speed limit out in West Texas is 80 MPH.. I was out there about a year ago. There really isn't much out there.. no merging traffic to deal with, because there is nothing on the sides of the highways (no buildings or gas stations). Pour the coal to it and let it roll.
They recently raised the limit on I-10 to 75 MPH for everyone, including 18 wheelers, day and night.
I'm so used to driving 65 everywhere though... I kind of do it automatically. Every time I look at my speedo I'm going 65. Sucks, because I hate to be "that asshole" holding up traffic, cruising under the limit.
As far as my point of view on raising the limit... there are always going to be people who want to haul ass. But, cars nowadays are built to handle speed more reliably and safely than long ago.. better suspension/brakes, traction control, you name it. Granted, there are more cars on the road than there used to be.
Maybe raising the limit will encourage people who prefer to drive 10 under the limit to drive a little faster. I can understand driving slower if inclement weather is present; the idea is to be safe (drive slower) but in clear weather, even if they are driving slow to be safe, if someone is driving a lot slower than the limit (and MUCH slower than the "constant flow" which is typically 80+) they are only creating more of a hazard.
Personally, unless I am in Houston (and everyone is doing 85+) I don't like driving faster than 80. The amount of time you have to react while catching up to someone driving 55-60 is very small.