Nickelback should go away, now!!!! I know a cop who lives in BC that arrested the lead singer. Way to go!
As for the one-hit wonder, it's now the 4-hit wonder. A band like the pussy-cat dolls or fergie will release 4 or so popular songs (that actually suck) and then they'll fade to obscurity.
Let's take a trip down memory lane, shall we?
Turn on the radio in the 60s. What to you hear? The Beatles, The Rolling Stones, David Bowie, The Who. All of these artists are still played today.
Turn on the radio in 70s. Led Zeppelin, Paul Simon, Bruce Springsteen, John Lennon.
The 80s. This is where I agree with you. The 80s was the decade of the one-hit wonder. Except, unlike now, the songs were catchy (and danceable) Tainted Love, You Spin Me Round (Like a Record), Forever Young, Karma Kameleon. On top of that there were huge artists like The Smiths, New Order, The Clash, Michael Jackson, and U2.
Let's skip to the 2000s. Nickelback (bweeehhhh!), Pussy Cat Dolls (garbage), Avril Lavigne, Evanescence, The All-American Rejects (at least their name is correct).
One of these decades is not like the other. Nowadays, if you want to hear good music, it's not being played on the radio. Did you happen to see this year's Crappys....er, I mean Grammys? The real music spreads through the underground The Arcade Fire, The Shins, The Postal Service, Bloc Party.