a better recycler than you

This morning, I ran across a reference to a story that I'd never encountered before.  I already knew that our solar system formed with heavier elements produced by the death throes of previous generations of stars.  What I didn't know, however, is that it's possible our sun formed on top of the dead core of one of those star supernovas (SN).

"Cores of the inner planets grew in a central iron-rich region; the Sun formed on the collapsed SN core."
- http://xxx.lanl.gov/ftp/astro-ph/papers/0411/0411255.pdf

Apparently this idea has been around for decades.  Why am I just now hearing about it?  Doesn't this story have grave implications about the lifespan of our host star?

In related news about remnant pieces of star formation, a small asteroid recently flew so close to Earth that it's trajectory changed considerably.  But you already knew about that incident because you've heeded my advice to watch the local conditions and forecasts at SpaceWeather.com, right?