For the tech sector specifically, there also was news this week that cheered IT market watchers. Apple's launch Wednesday of the iPhone 5, due to go on sale next Friday, spurred hope that it will not only fuel the market for mobile devices and services, but also help the overall economy.

"We believe the release of iPhone 5 could potentially add between 1/4 to 1/2%-point to fourth quarter annualized GDP growth," said Michael Feroli in a . JP Morgan forecasts that 8 million of the new iPhones will be sold in the fourth quarter alone.

The forecast on the effect of the sales on U.S. gross domestic product caused a stir, and elicited some ridicule. But Nobel Prize-winning liberal economist Paul Krugman, a New York Times editorial page writer, supported the basic logic of the concept. Though iPhones are made outside the U.S., "most of the price you pay when you buy one is domestic value-added -- retailing and wholesaling, advertising and profits -- all of which counts as part of G.D.P.," he noted in an opinion piece Friday, adding, "It's all pretty straightforward."

Apple is also boosting the PC market, according to other analysts. Fueled "almost entirely by sales of Macs and iPads, the PC market is the only segment of the computer hardware market that will grow in 2012," according to Forrester's new global tech spending forecast, released this week.

Stirring hope for revenue growth at Facebook, meanwhile, at the TechCrunch Disrupt conference in San Francisco that Facebook's new app for Apple's iOS mobile OS and a forthcoming app for Android will help it reach more users on mobile phones, and in turn generate ad revenue due in large part to the sheer number of users on mobile devices.