All the naysayers on bonds make my contrarian side kick in:
This article points out that while bonds may be at all time NOMINAL lows, they are NOT at an all time low based on real returns.
As the author notes what current bond jumpers are doing is chasing performance, ie market timing.
Also, what seems important to me is that bonds are supposed to blunt volatility, not guarantee against losses. Since CAGR is so badly affected by volatility, anything that lessens volatility ought to help improv CAGR.