A difference without distinction IMHO.
Not really. As an example, if implementations or ideas presented weren't based on actual touch technology then that alone may disqualify it as prior art.
As I challenged Christian, there's a lot of people who think prior art was obvious based on mistaken assumptions of what the patents actually claimed. I'd love to see someone explain their position in the form of, "Evidence XXX presented by Samsung invalidates Apple patent YYY because ZZZ."