Gallup has examined the May approval ratings for the Post-World War II Presidents elected to their first term (which is pretty much all the Presidents for whom we have data, since Gallup didn't start measuring approval ratings until FDR's third term) and concludes:

So far in May, Barack Obama has averaged 65% job approval. Since World War II, only three of the previous eight presidents elected to their first terms -- Dwight Eisenhower, John Kennedy, and Ronald Reagan -- have had a higher average approval rating in May of their first year. Obama's average exceeds those of the three most recent presidents -- George H.W. Bush, Bill Clinton, and George W. Bush.

The Atlantic piles on:

Analysts have likened Obama's '08 victory and massive popularity to Ronald Reagan's--saying Obama has ushered in an era of Democratic dominance akin to what Reagan did for the GOP. Given the relatively low ratings of presidents since Reagan, Gallup's data seem to support that--but we have to remember, it's only May of his first term.

Maybe.

Gallup is correct that only three other post-WWII Presidents elected to their first terms have had higher approval ratings in May.  But besides Obama, Ike, Kennedy and Reagan, there have been only five Presidents elected to their first terms since WWII.  One (Carter) had the exact same approval rating as Obama, and two had marginally lower ratings (Nixon at 63%, GHW Bush at 60%) and two had significantly lower ratings (Dubya at 55% and Clinton at 45%).  What we really have are two Presidents with sky-high approval ratings, two Presidents with mediocre-to-poor approval ratings, and four Presidents with approval ratings comparable to Obama's.  An equally valid interpretation of Gallup's data is "Obama's May Approval Ratings: Middle of the Pack."

As for the Reagan Revolution revisited theory, time will tell.  Reagan had solid approval ratings in May, yet his party suffered the sixth-worst midterm defeat in the post-war era eighteen months later.  Had the recession lasted a few months longer, we may have been looking back at Reagan as an accidental President.  Carter had approval ratings similar to Obama's, and yet he did not exactly re-invigorate liberalism.

Nor would I read too much into the fact that Obama beats out recent Presidents in their May approval ratings.  Bush II and Clinton both came to office with asterisks attached to their names.  Democrats believed that Bush stole the Presidency outright.  Clinton came to office with almost 60% of the country having voted for someone else, while Republicans believed that he had only won the Presidency because of Ross Perot and a pliant media that continued to hype a recession that had ended over a year earlier.

In other words, there's a reason that Bush II and Clinton's approval ratings softened so early -- a large number of people not only disliked them, but questioned the very legitimacy of their election.  But regardless of how Republican partisans feel about Obama, few question his basic legitimacy -- he was elected fair and square.  Given that, it isn't all that surprising that Obama's approval ratings are a reversion to the Post-WWII norm.  And given that it has been so long since we've had a President that the country accepted as legitimate off the bat, its no wonder that the press corps is in awe of his sustained approval ratings.

So I don't think there's anything we can read, either positive or negative, into the Obama's approval ratings right now.  He may well reshape the basic American political alignment, or he may march the Democrats to their doom.  It is far too early to tell.

As an aside, note Gallup's definition of its dataset: "May approval ratings for the Post-World War II Presidents elected to their first term."  There's a good reason for doing that to try to keep the apples compared only to the apples, but that definition does excludes three Presidents: Truman, LBJ, and Ford, who were not elected to their first term.  If we look at their approval ratings five months after they became President, Truman was at 75%, LBJ was at 77%, and Ford was at 37%.  If we look at their approvals five months after they were inaugurated to their first full term, Truman was at around 53%, and LBJ was at 70%.  So no matter how you define your dataset, Obama is still pretty much at the middle of the pack.

As a final aside, I think the Atlantic needs to step up its factchecking.  Note this in the article: "Unemployment was around 8 percent when Carter took office, and then continued to rise (up to 9 percent--around where it is now), but peaked early that year and declined for the rest of 1975. Carter remained popular despite the early rise, and then things started to turn around."  Note then that Carter was not, in fact, elected in 1974.  Nor was he in office in 1975, when unemployment spiked at 9%.  Unemployment was down to 7.5% when he took office -- 1.5% off of its peak -- and continued to decline until it bottomed out in early 1979.