Underlying much of the optimism: the unusually high amounts of cash sitting on the sidelines since the financial meltdowns of 2007-2008. Driven by lack of confidence, increased borrowing and other factors, the 1,000 largest U.S. companies had $853 billion in cash reserves at the end of 2010, up more than 6% from 2009, and up 33% from 2008 and nearly 75% from 2005, according to .

"There was definitely a recovery of M&A up to a few weeks ago," says Edward Schultz, a partner at the Tatum executive outplacement firm. "There seems to be less M&A going on right now, and when it does go on it tends to spark interest. A lot of (clients), they're holding up buying right now. There's a lot of wait and see."

Schultz has performed the finance function at several companies over the past 12 years, including at Hanson Industries, a $3 billion manufacturing, consumer products and services company, where he integrated five corporate acquisitions, and acted as CFO/COO of a foreign consumer products subsidiary.

"Valuations may be down," he says. "But by the same token one has to do more due diligence when the economy is questionable. Nothing substitutes for good, strong financial due diligence. It can't just be a P/E of so-and-so implies a valuation of so-and-so."