Am I loosing my time with API?

after a few chat with a friend, I got a little confuse. He said something like "API is obsolete after Windows XP release".

How the the new features and changes of Windows XP affects the API??
What kind of (API)compatibilities exists and what is the API tendency?
Is worth to program with API (not in *rapid dev ways*) or it is obsolete?

Jester

nothing's changed. all of my API code works in XP. the only problem I had was compiling code in V.xNET and running it in XP. It works on VC6 still, though.