For the past 18 months, CEO Sergio Marchionne has been holding Chrysler together with spit, baling wire, and a lot of airy promises about the future while he hurries through a reworking of the product line.

This month, the promises begin to be replaced by deeds, and the early results are giving pause to doubters of Marchionne’s ability to deliver on his promises. In particular, the all-new Dodge Durango could be the harbinger of a very big year for Dodge.

That will surprise a lot of people. Shortly after taking over Chrysler in June 2009, Marchionne made his most controversial move by stripping Dodge of its most iconic model, the Ram pickup truck, and splitting it off as a brand of its own. Shrunken to four passenger car models, two crossovers, and the Grand Caravan minivan, Dodge now looked like a shadow of its former self.

Despite the radical surgery, Dodge sales have held up surprisingly well in 2010, up 23% for the first 10 months. And that’s just the beginning. Now Marchionne is restocking the shelves at Dodge with a vengeance. Six all-new or significantly revised models are coming for the 2011 model year.

First out of the box is the all-new Durango. As an old body-on-frame sport-utility vehicle based on the Dakota pickup, the previous vehicle carrying the Durango name was such an embarrassment and performed so poorly that Chrysler’s previous owners (remember Cerberus Capital Management and its CEO Bob Nardelli?) put it on hiatus for the 2010 model year.

Except for its third row of seats, the 2011 Durango shares nothing in common with the old one. In place of the body-on-frame assemblage of its previous incarnation, based on the Dakota pickup, it gets a unibody platform that it shares with the Jeep Grand Cherokee.

That’s something of a mixed blessing. Though nobody ever thinks about it that way, the Grand Cherokee was one of history’s first crossover vehicles. But since it is ruggedly engineered for off-road use, it is substantially heavier than most crossovers, and the Durango shares its heft, weighing in at close to two-and-a-half tons.

Except for its mediocre EPA fuel economy estimates of 16 mpg city/ 22 mpg highway, the Durango wears its weight well.

This is an exceptionally handsome vehicle in a segment not known for its good looks. The old pig-snout front-end has been replaced by a forward-leaning four-section grille with a pronounced chin spoiler that looks aggressive without being ferocious. The Durango’s flanks are shaped with unusual suaveness for a crossover, with a subtle character line to lend visual interest.

The interior has also been smartly redone. The speedometer and tachometer dials look particularly sharp and a nice one-piece plastic cover for the dash replaces the usual jigsaw of individual pieces. Switchgear from the Grand Cherokee fits the decor, but the center stack and touch-screen graphics look like holdovers from another era and detract from the overall contemporary feel.

The second row of seats was roomy enough and two more passenger spaces are located in the third row for the athletically inclined.

My Blackberry Pearl test vehicle came in mid-level trim, which has been designated “Crew” for some reason. Crew is half-way between the base “Express” and top-of the line “Citadel.” The nomenclature is no more or less confusing than the usual DX, EX, SX, and LX, and the logic behind it is mysterious.

Base price for the Crew, which comes with a nine-speaker Alpine audio system and 6.5-inch touchscreen, keyless entry and start, and a power liftgate is $34,680. For another $3,450, I got 20-inch aluminum wheels, leather trimmed and heated bucket seats, and rain-sensitive windshield wipers. Total as-tested price: $41,320.

The good news is that both the Express and the Crew are powered by Chrysler’s new V-6 Pentastar engine connected to an older five-speed automatic transmission, which produces 290 horsepower in a smooth, seamless manner not previously associated with Chrysler powertrains. For a 16-foot vehicle, the Durango drives small, accelerating with enthusiasm and cutting turns with relative ease.

So many Chrysler products in the past felt unfinished or so thoroughly scavenged for cost savings that they looked and felt like they had come from the nearest strip-mall dollar store. The Durango, by comparison, feels fully developed and thought out.

In a segment populated by Ford (F) Explorers, Buick Enclaves, and Toyota (TM) Highlanders, the Durango doesn’t set any benchmarks, but it makes Chrysler competitive in a segment where it hasn’t been before.

And it makes you look forward to seeing what else Marchionne has up his sleeve for Dodge.