Umm, I think perhaps if you look in the top 40 you might find that no new music is very interesting but from my point of view, I'm not sure that I entirely agree. We tend to remember the best music of any period, or the worst in the case of the 80's, and it seems as if there were thousands of grat songs being written all the time back in the 60's and 70's, as oposed to only a few good songs now. However, there was a lot of crap being produced then, and there always will be. Think of the Monkeys. However, you have a point, it does seem harder to find musicians these days who are more than one hit wonders. Here are few who are I think.
Pearl Jam: They are consistently creating music with integrity and soul. They don't advertise much, or create vido clips, because of how wary of the music buisness they are.
Radiohead. Another rock band that has integrity.
U2: They continue to innovate with new styles and at the same time have managed to not become gimmicky or bland.
Bob Dylan: Still rocking on, possibly he doesn't count cause he started in the 60's, but he continues to write new songs of merit.
FatboySlim: Some might disagree, but I think he is one of very few artists of his kind that is creating new music that is popular yet musically interesting. Time will tell whether he endures.
Red Hot Chili Peppers
Madonna
REM
Rage Against The Machine
Anyone else have some more? There are more bands that I like, but haven't listed, these are the bands that although I don't particularly like some of them (ie RATM), I think they are bands that go against the trend of one off hit bands.