Rather than being genuinely "new" I'd say that modern programming languages are gradually bringing in ideas which have been known about in computer science for decades, but haven't really hit industry - or which have previously been in niche languages, but not in mainstream ones.
For example, many of the ideas of LINQ aren't new per se - but for many developers LINQ will be their first experience of them.
Think of it as a process of "productising" previously "experimental" features. When I talked with Eric Lippert recently he said that the C# team was trying to avoid including "open research" ideas into the language - simply because they can't tell whether or not those ideas will pan out in the long run. There's plenty of room for experimentation in language, but probably not in mainstream languages.