As an aside to your edit, I have also seen "different than" used more and more often of late. I'm not sure if it is an Americanism that I was just unaware of. It's not that "different than" is wrong, it's just different from what I'm used to!
To this day, I still can't remember which is correct - "than", "from" or "to". But I can remember the look on his face, and the fact that after that he stuck with slightly less aggravating teaching methods.
I believe that "different from" is most common across all dialects of English: http://alt-usage-english.org/excerpts/fxdiffer.html (Note: This only compares UK English and American English, not "all dialects".)