Cautious optimism is the order of the day. Ahead of its Dec. 16-17 monetary meeting, the Federal Reserve offers some holiday cheer: Hiring is picking up nearly everywhere. Consumers are pocketing disposable cash as gas prices plummet. Sales of autos and appliances are brisk in many regions. A shortage of skilled workers is lifting salaries in New York, Chicago and San Francisco, although overall wage growth is standing still. Just don’t expect Saudi princes to dole out billions like before.