Very poor US opening:
http://www.hitfix.com/news/box-office-m ... tand-flops
I wouldn't be too worried yet, though. I think Schwarzenegger (and many other 80's icons) remain much bigger stars in Europe, Japan, Russia etc. than they are in today's USA. For example look at The Expendables 2: $85 million domestic box office vs. $215 million international. I could imagine The Last Stand being a success in markets like France.
It's also a relatively "cheap" movie, costing only 30 million to make (IMDb estimation). Of course the advertising budget may add quite a bit to it, but I still think the film will easily break even thanks to the international market alone. And the reviews have been positive, so the US box office might catch (more) fire after a little while when people figure out the film is probably a good one.