Nokia today posted fourth quarter earnings, and the results aren’t pretty. The Finnish handset maker saw a profit of $1.02 billion, marking a 21 percent slide from the year-ago period. And while overall sales rose, Nokia’s share of the booming smartphone market shrank to just 31 percent, down drastically from the 40 percent share the company claimed during the fourth quarter of 2009. What growth the company is seeing appears to be coming from low-end feature phones, which underscores how antiquated and unwanted Symbian OS has become in the superphone era. Meanwhile, MeeGo continues to spin its wheels, so there’s little hope for a short-term, in-house solution. Which is why the company seems to be considering moving to a different OS — either Android or Windows Phone 7. Don’t be surprised if it makes a move sooner rather than later.