Depends on how you look at it. Yes job losses really suck, especially if you're the one getting the slip. But from an investor's standpoint, they are an absolute necessity and may be viewed in the positive.
Corporations and public companies have become obese on the bubble. Now they need to go on a diet. When they drop some of that weight, whether it be pealing off a non-producing arm of their company or dropping their surplus of employees, they will become leaner and more efficient versions of themselves. Ultimately in the long run that will lead to profits, better profits-per-share ratios, and that will trigger stock price increases.
I wouldn't be surprised to see short-term jumps in the stock prices of companies that announce layoffs, as investors speculate about their more profitable future.