Current analysts have a 2012 election that is either too close to call, or have Obama easily winning it in November.
The obvious problem most see with the GOP chances is that they have no candidate to unite them and give them that excitement that is necessary to topple an incumbent, even one as unpopular as Obama. And that won't change. Let's face the facts, Romney is a bland candidate that evokes memories of 2004 John Kerry.
Two things that could improve the GOP's not -so-great chances are if there is an international incident, or a financial/gas related one. Those two cards are the incumbent's to lose, and so far there is no indications of any of those happening. My guess is gas prices will be controlled, as well as any desires to attack Iran. The third card is in the hands of the SCOTUS. In June, they will decide on the constitutionality of the health care Individual Mandate and Obamacare as a whole.
Most see the SCOTUS ruling against Obamacare as not significantly changing the 2012 landscape, and it might actually help Obama a bit since future GOP attacks about it would have little effect.
But in the chance that somehow the SCOTUS upholds the Individual Mandate, this would give the GOP what they have been missing: a silver sword, a most powerful weapon to take down Obama.
Some also say that Romney is tied to Obamacare (through his Massachusetts universal health care plan), but I don't see this hurting Romney. It has not hurt him so far. He was already attacked fiercely by other Republicans for his role on health care, he is running on "repeal Obamacare" and nevertheless he is still winning the GOP vote handily.
If you have doubts on the powerful unifying effect of Obama's health care law on the GOP, just rewind the tape to 2010.
The recent Tea Party movement was in no small part started as a backlash to Obamacare. Right-leaning citizens were so outraged at the spending, taxing and laws such as Obamacare, that they united in such a way as to directly affect the congressional elections of 2010. This movement helped the Republican Party take control of the House in Congress. At the Tea Party rallies, you could see citizens outraged at the mention of Obamacare, termed by them as "Socialized Medicine." In other words, the mention of Obamacare was as effective to rile up the Tea Party troops as any other term. One could conclude that the success of the Republican Party in 2010 was in no small part thanks to Obamacare.
If SCOTUS were to rule in favor of this law it would be Tea Party times 1000. That is how outraged many right-leaning and independent voters would be. And all that outrage would be coming out with perfect timing to build into a boiling point in November. The GOP base would be completely unified, many independents would side with them as well as most, if not all, the Ron Paul followers and other fringe groups. I don't see Obama as the favorite under that backlash and anger, actually if Obamacare is upheld I don't see Obama winning in November.