Remember when I wrote that Iron Man 3 could be a billion-dollar film? I may have been lowballing some. Early reviews of the film are in and they're spectacular. Better than Marvel's The Avengers, a $1.5 billion blockbuster.

Rotten Tomatoes says 29 of the 31 reviews thus far compiled at its site, or 94%, rate the film fresh. The Avengers rates only slightly lower at 93% while 73% liked Iron Man 2.

"[Robert] Downey [Jr.] is at his superhero genius best here, rattling off dialogue both clever and boilerplate with non-repetitive aplomb," wrote The Hollywood Reporter's Todd McCarthy. He went on to predict that IM3 "will be the (early) summer's first massive hit."

Time Out London offered a more muted assessment in time for tonight's international premiere, calling the film worth seeing, though "something of a disappointment" when compared to The Avengers. Negative reviews hardly come more flattering.

Obviously, the numbers could change over time. History nevertheless proves that early enthusiasm can become contagious. Strong reviews have led to even stronger box office performances in years past:

Walt Disney (NYSE:DIS) chief Bob Iger must love seeing those numbers. Disney purchased Marvel for $4 billion in 2009. One character's solo adventures has already paid back more than $1 billion. Iron Man 3 could double that.

Marvel peer DC Entertainment has yet to find a comparable win with its characters, which is a problem for parent Time Warner (NYSE:TWX). Only Batman gets close. According to Box Office Mojo, Downey's Golden Avenger averaged $332.1 million in inflation-adjusted gross receipts over his two solo box-office appearances. Batman averaged $330.6 million on the same basis, while Superman -- the genre's most recognizable name after 75 years of appearing in the comics -- averaged just $237.9 million.

Or to put it in terms comics fans will appreciate: When it comes to the box office, so far, Downey's Iron Man has proven to be invincible.

Sources: Marvel Entertainment and YouTube.

Will you see Iron Man 3? Or if you've seen it already, what did you think of the film? Please leave a comment to let us know what you think and whether you'd buy, sell, or short Disney stock at current prices.

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