Exactly. Moreover, Santorum and Gingrich are free to concentrate on those states where they each have the best chance of winning -- putting up token opposition in the states they are each likely to lose.
Gingrich's and Santorum's competitive problems are lessened, while Romney's are doubled.
By the same token, it's way too early for conservative voters to be committing to one or the other. We should all recognize that a.) we don't know yet whether Newt will implode and b.) we don't know yet whether Santorum can hold up over the long haul.
Why make tht decision until you have to?
Certainly, there is no need to make it before April 1 -- when some primaries become "winner take all".
As long as both are in the race, Mitt has to focus on both, he has no choice. He has to divide his resources and his attention.
As long as both are in the race he won’t lose decisively.