Seeking a barometer to gauge whether General Motors has the wherewithal to rebuild its flagging vehicle brands and engineer a successful turnaround?

Look no further than GM’s Saturn division, which is on the verge of a make-it-or-break-it new-product renaissance.

Saturn has been the poster child for neglect almost since its inception in 1990, when it began with a small car and got little in support ever since.

A bland midsize sedan, the L-series, was added in 1999 but flamed out quickly. The me-too Relay minivan that bowed in 2004 never really took off with buyers, with sales this year totaling only 2,348.

The Vue has performed better in the SUV-crazy U.S. market and now is the choice of nearly half the brand’s customers. Overall, however, Saturn sales have languished, falling from 280,248 in 2002 to 213,657 last year.

But at last month’s New York auto show, the division pulled the curtain back on its future, unveiling the new, more upscale midsize Aura sedan and Outlook cross/utility vehicle that go on sale later this year.

It also showed off a concept for the next-generation Vue and rolled out a high-performance version of its new Sky roadster that hits dealers this fall. Mild hybrid-electric versions of the Vue and Aura are on their way, as well.

And although Saturn officials aren’t talking, the Ion small car likely will be replaced by a carbon copy of the new Opel Astra sold in Europe. An Opel-based large car also may be in the cards.

All-in-all, GM is making a big-money bet on Saturn’s future, and in return the auto maker’s second-youngest brand is being counted on to help kick-start a corporate-wide renaissance.

The new models are cleanly, but not boldly, styled and boast some clever features, such as the Outlook’s “Smart Slide” flexible seating that eases access to the rear and enhances cargo-carrying capability.

But it’s a dogfight out there, and it remains to be seen whether the new merchandise will resonate with those buyers that have shunned Saturn showrooms in the past.

Whatever the outcome, it could be a harbinger for GM, which still has serious work ahead to revitalize several of its other brands.

In recent years, much of GM’s product success has been with its cornerstone divisions, entry-level Chevrolet on one end and luxury-brand Cadillac on the other. Sales of those marques are up 5% and 38%, respectively from 10 years ago, and each can point to a few bona fide hits.

More murky is the middle ground, where Pontiac, GMC, Buick and Saab reside. Much needs to be done to redefine those nameplates with new models before critics can be expected to stop suggesting the auto maker would be better off without them.

Until then, all eyes will be on Saturn.

If the revival works, then just maybe the auto maker has what it takes to breathe life into its other long-dormant brands.

If it doesn’t, it may not doom GM to failure, but it won’t exactly inspire confidence either.

dzoia@wardsauto.com