In a world filled with brand extensions, it was perhaps inevitable that the world's favorite diet cola would enter the era of health consciousness. But really, did anyone foresee aspartame and vitamins commingling in the same bottle?

Diet Coke Plus is the latest answer to consumer weight and health concerns, as well as the sagging soft drink industry. In March Coca-Cola's chief executive, E. Neville Isdell, told the New York Times, "Diet and light brands are actually health and wellness brands," asserting that "Diet Coke Plus was a way to broaden the category to attract new consumers."

With water, sports drinks, and other alternative beverages gaining market share over the last few years, soft drinks—including diet and light versions—are losing consumer dollars, some say due to the full-sugar versions' links to rising obesity. According to Beverage Digest, the decrease in the number of cases sold from 2005 to 2006 is 4.8 percent for Coke Classic and 2.2 percent for Diet Coke. Coke faired a bit better than rival Pepsi, which saw sales of its sugared and diet colas down 6.2 percent and 3.6 percent, respectfully.

According to a press release, Diet Coke diehards needn't worry that their favorite vice is going anywhere. The staple Diet Coke, along with flanker sub-brands Caffeine Free Diet Coke, Diet Coke with Lime, Diet Cherry Coke, Diet Coke Sweetened with Splenda, and the new Diet Coke Plus are simply variations on a calorie-free theme meant to offer more options and—bottom-line—attract more drinkers.

Design-wise Diet Coke Plus cans and bottles fit right into the existing Diet Coke brand architecture, sporting the same common elements as the original Diet Coke and adding the new brand's own color swatch of aqua to the famous Coke ribbon and bottle caps. The "Plus" part of the design equation features a rather retro, 1980s-looking type treatment with a small "flower" peaking out from the left side and a gradated rainbow on the letters, presumably to evoke a rainbow of foods and a spectrum of vitamins and minerals.

"Great Taste Has Its Benefits" as the product's tagline works well to play off of the "Great Taste" equity of Coke and Diet Coke while indicating the "something more" aspect of the drink. The product packaging also features the phrase "Diet Coke with Vitamins and Minerals" just beneath the Coke ribbon, the latter of which is in all caps.

Between the added communication point and the rainbow, the lower half of the can begins to conjure images of Centrum multivitamins, which wouldn't seem so incongruent if not for the fact that rather than an array of vitamins and minerals cohabitating with the other Diet Coke ingredients, there are, alas, only five.

Each eight-ounce serving is reported to provide 15 percent of the recommended dietary allowance (according to the US Department of Agriculture) of niacin, vitamin B6, and vitamin B12, and 10 percent of the allowance for zinc and magnesium. Interestingly enough, the drink does not provide calcium—one of the key minerals said to be lost when caffeine is consumed. Commenting on the ingredients, one blogger laments, "Why not just take a multivitamin with a [regular] Diet Coke?"

Not surprisingly, the blog-based bashing of Diet Coke Plus has already begun. Comments range from complaints about the drink's sweeter taste to incredulity regarding the notion of a "nutritious" Coke drink. In the coming months Pepsi—no idle brand itself—is releasing its own vitamin-fortified, caffeine-free Tava, which includes the mineral chromium, said to boost metabolism and enhance weight loss.

As one would expect from the two titans of soft drinks, this latest battle for taste buds, health, and bucks should be in full swing by the end of this year.

Have an opinion about Diet Coke Plus? Join the debate!

Alycia de Mesa is a brand consultant, speaker and writer with more than a decade of industry experience ranging from start-ups to Fortune 100 companies. Her latest book is Brand Avatar – Translating Virtual World Branding Into Real World Success (Palgrave-Macmillan).