The reality is that Romney is very likely to be the nominee. Is it possible that Santorum could overtake him? Yes. But it’s more likely Santorum will give him a good challenge, but end up finishing a strong second overall.
Gingrich will quickly become a non-factor, except to the extent that his attacks on Romney push fiscal conservatives to Romney and social conservatives to Santorum. While his attacks have dented Romney a little bit, the political benefit has not redounded to Gingrich, nor will it in the future, imo.
Unfortunately; Romney = second term for Obama.