Despite some models costing upwards of $100,000, the luxury flagship sedan segment is one of the most hotly contested in the industry and is currently dominated by five main players: the Lexus LS, BMW 7-Series, Jaguar XJ, Audi A8 and Mercedes-Benz S-Class.

We’ll soon be able to add a sixth challenger to that list in the form of the 2012 Cadillac XTS, which was previewed today in concept form at the 2010 Detroit Auto Show and is destined to serve as the replacement for the STS and DTS lines when it arrives in early 2012.

Officially titled the XTS Platinum Concept, the Detroit concept vehicle emphasizes the Cadillac's Platinum line of range-topping models while also reigniting interest in GM’s plug-in hybrid technology.

That’s because the XTS Platinum Concept using Cadillac’s existing 3.6-liter V-6 direct injection engine and pairs it with a plug-in hybrid system. This combination allows the vehicle to coast effortlessly along on electric power alone, while at higher speeds or when conditions demand it, such as brisk acceleration, a combination of engine power and electric power or engine power only propels the vehicle.

The combined output of the advanced powertrain is a respectable 350-horsepower and 295-pound-feet of torque. When not in use, the vehicle can be charged at any standard external electrical outlet and takes about five hours to fully recharge.

In this way, drivers can experience efficiency that doubles that of conventional hybrids--not bad for a large luxury sedan. Note that this set-up is different to one in the 2011 Chevrolet Volt, which relies solely on its electric motor for propulsion and uses its internal combustion engine to top up the battery.

It’s not all about the powertrain, however, as the XTS Platinum Concept also features Magnetic Ride Control (MRC) adjustable shocks and an all-wheel drive system. Four-wheel disc brakes, with four-channel ABS, StabiliTrak stability control and full-function traction control complete the chassis details.

Cadillac XTS Platinum Concept

Cadillac XTS Platinum Concept

Of course, no luxury flagship sedan is complete without an opulent and technologically advanced interior to pamper passengers and the XTS Platinum Concept certainly doesn’t disappoint in this area.

The vehicle was designed from the inside out, re-imagining the luxury sedan as a personal headquarters, built for efficiency, luxury and connectivity. For example, the cabin features organic-LED displays in place of traditional gauges and screens, hand crafted leather surfaces and a touchcreen interface for the navigation system.

Light cream is the cabin’s primary color and is contrasted with darker elements, such as the steering wheel and an overhead console motif that runs the length of interior’s roof. The console is made of a richly finished wood and is detailed with ambient lighting features. Designers have also added a touch of flair by applying lots of suede throughout the cabin.

Production of the 2012 Cadillac XTS is scheduled to start at GM’s Oshawa, Ontario plant in early 2012, with first sales to start shortly after.