In one sense, standard investing advice is to periodically rebalance between investment classes when your holdings diverge too much from you desired profile. In this, for a "simple" investor, that would probably mean transfering from bonds to stocks; since the portion of your portfolio that is in stocks recently fell substantially below your desired portion.
Assuming an efficient market, it is almost a no brainer that you should rebalance. Since your risk profile didn't change from a month ago, and stocks are being correctly valued, your portfolio is now overly conservative.
If you dont believe the market is effiecient, the question becomes 'in what way is the market inefficient?'. If you believe it is now undervalues stocks, you should buy them since they are now on sale for a bargain price.
Personally, my view is that the market is irrational, but I don't know how; so I am planning on not reballancing until after the dust settles. This minimizes the downside risk caused by me not knowing what I am doing.