I have a good feeling that Ke$ha's next era may be coming sooner than we think...
I think I've said this before, but my radio station usually plays old tracks from artists that have new material coming out, as a way to build hype around the artist. For example, before ARTPOP and PRISM were released (or even formerly announced) they played Gaga's and Katy's older singles a lot more than usual.
Recently they've been playing some old Fergie songs, and as we all know, Fergie recently announced that she's wanting to work on a new solo album before The Black Eyed Peas' next release.
As well as Timber, they've been playing Ke$ha's old singles too, such as TiK ToK, We R Who We R, Blow and Die Young. I forgot about it for a while, but just today they played Blow on the radio.
So either they think that Timber is Ke$ha's song from a new album (unlikely), or Ke$ha has new music coming soon... or I guess they could just be playing her old songs because she's back on the radio, IDK. But knowing my local radio station, they wouldn't just play old songs like TiK ToK for no reason...