Moody's cut Greece's debt rating to A2 from A1 Tuesday, sparking a rally in the country's bonds as the cut was less aggressive than anticipated. Greek Finance Minister George Papaconstantinou told CNBC the downgrade was a positive surprise.

"We're really glad to get rid of 2009," Sir Martin Sorrell, CEO of WPP, said. "2009 has been pretty brutal." He told CNBC the company "didn't budget very well" at the beginning of the year "but I think we got our house in order." WPP is forecasting flat revenues for 2010, according to Sorrell.

2009 started "very turbulently" but we are slowly getting "more clarity and slightly more visibility, so all in all a year of good lessons," Michael Wolf, CEO of Swedbank, said. "What the G20 is trying to achieve is really good for retail banking – we're moving back toward a more traditional banking view."

"There is a little bit of a growth pause likely to show up either in Q4 GDP or in Q1 GDP for euro-land," James Shugg from Westpac Bank told CNBC Friday. Geoff Kendrick from UBS joined the discussion.

We are ending the year and the decade with news from Brazil, India and China "being an increasingly dominating thing for the world economy," Jim O'Neill from Goldman Sachs said Friday. "What goes on in those places, particularly China is as important, if not more, than the US, in my opinion," he said.

"We've got an awfully big public sector deficit (in the UK) that we're not dealing with," Michael Taylor from Lombard Street Research told CNBC Friday. "Without quantitative easing you could say we would be in an incredibly severe monetary squeeze," he added when considering the outlook for the UK economy.

"We need a bridge of time… during that bridge of time we can survive," Greek Prime Minister George Papandreou told CNBC Thursday. "We need a breather from the rating agencies to allow us to show them that in fact we can make a change in our country," he added.

UK retail sales fell unexpectedly in November, after relatively strong sales results in October. Marc Ostwald from Monument Securities told CNBC that the situation is worse outside of London because there is less tourism.