I know I'm kind of late to this thread, but this looks to me like one of those bright sunsets that simply has too much dynamic range to capture while preserving detail in both the highlights and shadows. That said, I know of two possible solutions. A graduated ND filter does wonders for sunsets like this, bringing the sky's exposure down while maintaining detail in the landscape. Graduated colored filters can also add some punch to the sky. The other method is to bracket like crazy (as much as 3 stops in each direction) using a tripod and merge the two or three best pictures in photoshop, perhaps using the HDR tool. I tried to take pictures of a similar scene (in terms of dynamic range) in the Tetons last year before investing in sone relatively affordable Cokin filters and it was impossible to avoid blowing out the sky without massively underexposing the mountains.
In order to conquer the HDR problem, use a tripod and take a minimum of two shots - one shot worries not about overexposure (just make sure the low to mid tones are up as high as you want them and let the highlights go to H--- in a handbasket). The other shot should be placed with the highlights just barely clipping if in RAW mode and not quite clipping if in JPG mode.
The "Merge to HDR" tool mashes everything into the 16 bit/channel space and you take it from there.


