All of the French Champagne houses that have operations in California call their American product "sparkling wine" for the reason plaw cited. Here's another fun-filled factoid:
One of the benefits of real Champagne (produced in the Champagne district of France) is that all Champagnes must be made via the methode Champenoise. As the still wine is bottled, a small dose of yeast and sugar is added, then the bottle is corked. The following spring, a second fermentation occurs in the bottle that results in a finer wine with smaller, livelier bubbles.
California sparkling wine could be made in any of three ways. The label holds the key. The poorest way is if it says, "Naturally Fermented - Charmat Bulk Process." This means that the wine was fermented, just like any wine, but the bubbles were forced in via CO2 injection. This is a swell way to make seltzer, but it sucks for sparkling wine. A second way is indicated this way: "Naturally Fermented in the bottle" [emphasis added]. Since US law doesn't define a "bottle," it means that a second fermentation occurred in some large container--like a 1,000 liter vat--and the wine was then put in smaller bottles. The authentic way is indicated by the phrase, "Naturally Fermented in this bottle."
Back to the original topic: Putting sparkling wine in a can isn't a bad idea, as long as you drink it when it's young and don't intend to age it. The can will enable you to chill it quicker. It'll also save lots of money: Champagne bottles are much thicker than standard wine bottles, and the layered corks cost a fortune compared with regular corks--much less pull-tabs.