And they're off! Two days ago, General Motors (NYSE: GM) returned to the public markets with what may have been America's biggest IPO ever, depending on whether you count preferred shares. Was the IPO a success? Will GM be successful? It all depends on how you look at these things.

Short-term price poppers
Say you saw this IPO as a chance to get rich quick off the initial pop above the IPO price. Chances are, you missed that chance.

First, the U.S. government hamstrung your efforts by distributing shares to the biggest banks, leaving many individual investors who trade through discount brokers out in the cold. Underwriters JPMorgan Chase (NYSE: JPM) and Goldman Sachs (NYSE: GS) will have profited from the spread between GM's $33 IPO price and the $35 at which trading opened Thursday morning.

Yet nothing warms the heart like schadenfreude. Thanks to a last-minute price increase, even those Fools lucky enough to snag a few shares at the IPO price wound up feeling jilted. In place of the promised 10% or 20% first-day profits, early investors got … neither. Sad to say, GM shares ended the day with less than a 4% gain.

Medium-term tea-leaf readers
Of course, even 4% is nothing to sneer at. Not bad wages for one day's work, if you're one of the nation's megabankers. But what comes next?

As I explained last month, the medium term looks exceedingly propitious for GM. Though no longer "Government Motors" (the feds' stake in GM has dropped way below a controlling 50%), GM is still very much President Obama's baby -- and you can trust that it will be well cared for over the next two years.

As GM tries to earn its way out of a bankruptcy-dug hole and grow to a size at which the government can sell it for enough money to repay its loans, GM can expect to receive TLC from the IRS. Fully $45.4 billion worth of tax-loss carry-forwards have been reserved for GM's use and will inflate the company's reported profits -- and depress its P/E ratio to mouth-wateringly low levels -- for years. It's all in the interests of making the shares look more attractive, driving the share price up, and moving toward the day that a U.S. president seeking re-election can proudly claim: "We saved GM and got all our money back, and it didn't cost the American taxpayer a dime."

Long-term true believers
Of course, even GM has its adherents. (Some, stubbornly so.) Rather than play the short-term in-and-out game on IPO day, or gamble that they've read the government's political policy on the company correctly, some investors will actually buy GM stock and hold for the long term. (Imagine that!) They'll gamble that, like Ford (NYSE: F) before it, GM will prove itself capable of reinvention. They'll buckle up and buckle down for the long haul.

And they may be right. After all, during its exile in first bankruptcy, then private ownership, GM made remarkable strides in improving product quality. It cut costs, renegotiated with union reps over deals made with the devil, and sparked the innovation engine with its brand new Chevy Volt hybrid-electric car.

Granted, when I look over the company's current car offerings, which arrive on a postcard offering to "top off" my GM bonus cash credit card nearly every month, I find myself uninspired by most. But the Volt, at least, intrigues me. Primarily battery-operated, it has that little gasoline engine that keeps it running long after Nissan's Leaf has run out of juice. General Electric (NYSE: GE) just gave it a jolt of confidence, by promising to buy 12,000 of the electro-buggies. And just Thursday morning (timed to coincide with the IPO, no doubt), Texas utility company NRG Energy (NYSE: NRG) announced that it's setting up the nation's first privately funded electric car-charging network.

Seems to me, the car's gaining in credibility by the day, and although some deride it as "just another hybrid," the Volt has nonetheless attracted praise in the pages of everything from Motor Trend to the The Wall Street Journal, while Popular Science called the car "something of a miracle." Considering that it's innovation and product lineup that ultimately determine the success of any car company, I have to say … it's a propitious start for an initial public offering -- at any stock price.

What do you think of the goings-on on this week? Was the GM IPO just a flash in the pan -- or does this car company have "legs?" Let us know in the comments section below.