A poll that's been circulating in the rightosphere today (pushed especially hard by Bill Jacobson over at Legal Insurrection) is this Gallup tracking poll showing Gingrich lagging Obama only by 2 points (48-50). Some in Gingrichistan are pointing to this poll as evidence of the fact that that Gingrich's new style is paying dividends not only with the Republican base but with the nation as a whole.
There's one problem with this argument, however: this poll is over a month old. Though this tracking data is featured prominently on Gallup's site (and Gallup doesn't provide a date for it on the main page of its election 2012 polling), it seems to stop by December 15-18, 2011. So this polling was taken well before Newt 1.0 was unleashed. (The Gallup chart conflates the GOP nomination polling, which is currently updated, with the general election polling, which is not.)
Many polls taken since then have shown Obama with a much bigger lead over Gingrich---most polls give him around a 10-point (or greater) edge. Obama's average polling lead over Gingrich has increased over the past few weeks. Moreover, this poll was probably an outlier even then; other polls taken around the same time show Obama leading by a much larger margin.
So if you're looking for evidence that Newt Gingrich has closed the electability gap, this poll probably isn't it.