In response to QcCowboy's comments;
Yes, in general, but as well as this a lot of modern concert music, especially British music, is going through a process of simplification: Howard Skempton and Laurence Crane are two good examples. Many of their pieces appear as if they are being viewed through glass cases: they have a kind of clarity, often extreme clarity. Of course, clarity, is by no means the same thing as simplicity. From a performer's standpoint, these pieces are often tricky as they require a certain degree of precision, but precision which is not mechanical; human precision, or precise imprecision.
A player who is interested in performing modern British concert music is often confronted with the most complicated notation for musical gestures (the "new complexity" group, which nowadays is neither new nor particularly complex, which included composers like Ferneyhough and Finnissy, was interested in this), and the intent of the composer is for the performer to attempt to play them, and in doing so create a valid representation of the piece (rather than have the thing played exactly, which might, especially in the case of Ferneyhough, be impossible). The Skempton school is related to this, but instead of the player having to come to terms with a piece of music they cannot play, they have to come to terms with a piece they can play, and with great ease most probably. They then must pay attention to each little nuance of sound and inflection, tone and colouration. With wind and string instruments particularly, this is often just as difficult as playing more complex figures, as the player's technique is far more exposed.
This is not even considering the American take on this approach - Morton Feldman being a prime example. Indeed his music is even more physical than perhaps the most difficult of pieces, just because of its extreme length.
Here are two contrasting piano pieces to demonstrate the idea.
Laurence Crane - Looking for Michael Bracewell (1989)
Michael Finnissy - Song 9 (1968)