The other day on CBC I heard a woman being referred to as devastatingly beautiful. It made me think of other cases where adjectives with negative meanings in common usage are used as emphatic compliments.

It was awfully good. He was terribly talented.

Three questions:
1. Can anyone think of other examples (I had another one but lost it on the commute to work.)
2. I have only heard this usage from British or British-educated people, never from Americans. Is this just a Commonwealth thing?
3. Any theories as to why these words, which over the centuries have lost their original positive connotations, have yet retained them in this construction?

I remembered the other one: Wickedly. He's wickedly funny.