Last summer’s unveiling of the all-new, next-generation 2010 Jaguar XJ sedan likely sent shockwaves through the design studios of other luxury brands. That’s no surprise. The first-ever Jaguar XJ did just that over 40 years ago.

The Beatles released their hit Revolution in 1968, a year when the luxury car market was ripe for a bit of revolution itself. It, too, would come from Britain in the form of the new Jaguar XJ6 sedan. You have to consider the luxury car landscape of 1968 to grasp the impact of that first XJ. What the unabashedly modern 2010 XJ design is to current luxury sedans, the 1968 XJ was to its contemporaries.

Forty-one years ago, American models – Cadillac, Lincoln and the Chrysler Imperial, were huge, slab-sided things that combined conservative shapes with ornate details. The leading European luxury sedans were from Jaguar and Mercedes-Benz; Rolls-Royce/Bentley occupied the top end and BMW was not yet a player in this segment. The upright Mercedes-Benz sedans exemplified European elegance, but were hardly exciting to look at.

Jaguar sedan designs already stood apart for their curvy figures. Models like the midsize 420 and full-size 420G had already established some core elements of “the Jaguar look,” especially the “face.” By the late 1960s, though, Jaguar was ready to give the luxury sedan the kind of kick that the XK-E had given to the sportscar world.

Arriving in 1968, the original XJ sedan was immediately hailed as a design triumph. While the front end neatly consolidated themes introduced on previous Jaguar sedans, the XJ’s profile was unlike anything seen in any sedan – luxury or otherwise. The roofline was daringly low, and so was the beltline, resulting in a generous glass area.

There was no mistaking a Jaguar XJ for anything else on the road. There wasn’t a line or feature seen on any other car at the time. While recognized as the most beautiful luxury sedan at the time, the XJ6 was also called the best driving luxury sedan in the world.

Interestingly, while no one called the 1968 XJ “futuristic,” other carmakers would begin to take inspiration from it – over 20 years later! Because owners were so enamored of the XJ’s sleek profile, Jaguar had to be very careful about updating the design. The basic body carried over for 18 years, and successor XJ models up until the 2009 model have been clearly related to that original.

How do you reinvent such a classic? Looking around, Ian Callum, Design Director, Jaguar Cars, could see that luxury sedans seemed to be aping each other and not really advancing the design language. As in 1968, the time was right once again to introduce a new paradigm.

Although the all-new 2010 Jaguar XJ looks nothing like its esteemed predecessors, it does display some modern reinterpretations of several classic XJ design cues. There is a contrast between the lower, muscular part of the vehicle and the roofline’s elegance and grace. According to Callum, “The new XJ is a thoroughly modern interpretation of the quintessential Jaguar."

A panoramic glass roof (standard) gives the 2010 a streamlined roofline while making the interior appear roomy, light and airy. The wraparound rear window makes the roof pillars look even slimmer, a hallmark of the original XJ design.

The 2010 XJ’s bold mesh grille and slim xenon headlights give it a confident face as if the car knows it’s going to be influential. The rear of the new XJ also shows a tapered look similar to that of the original XJ. The way the LED light clusters wrap over the rear fenders, when viewed directly, appears to recall the taillight shape on the original XJ.

Jaguar dealers are now taking XJ orders for delivery in early 2010. The new XJ will be available in standard and long wheelbase XJL models, the longer versions providing an additional five inches of rear legroom. The six models include the naturally aspirated XJ and XJL (385 hp) at $72,500 and $79,500 MSRP, the XJ and XJL Supercharged (470 hp) at $87,500 and $90,500 MSRP and the XJ and XJL Supersport (510 hp) at $112,000 and $115,000 MSRP.

Once again, there’s revolution in the air.