I wouldn't call Left Lane a highly credible source, particularly. I generally don't call journalists credible nowadays.
I have been on and off engaged in traveling sales, and just before they moved, I sold my wares at MBUSA's headquarters in Montvale, NJ. It was, frankly, the best building I have ever done in terms of the quality of people who worked there. I think that MBUSA is trying its best to get the feel of what their customers want. They are worried about this whole van enterprise, and have been since deciding to rebrand the Sprinter a Mercedes.
They are conscious of something both their dealers and their sedan customers don't want- and that is a degradation, in any way, of the exclusivity, prestige, quality, and reputation of Mercedes-Benz luxury cars. Of the brands that aren't "exotic" (E.G. Porsche, Maserati, Aston-Martin, Rolls-Royce, and Bentley) Mercedes sells its cars the most expensive, and they are the most prestigious. They cost more, and are considered worth more, than their general competitors (Lincoln [ha!], Cadillac, BMW, Audi, Lexus, Infiniti, Jaguar, and Acura). That is a priceless asset, which they are not going to squander on something as stupid as making a little money on selling a van.
No, for any product move to make sense to MBUSA, it has to be worth it in the overall big picture, remembering that while Europeans don't seem to have confusion seeing a 3-pointed-star on a $25,000 stripper Vito and a $255k S65 AMG on the same block, Americans do have that problem. They rejected the VW Phaeton, a car that in engineering terms blew the W220 S-class out of the water- for much less money!
I think that demand is going to cause the importation of the diesel model and probably the 4x4. I think that if enough people request them from their dealers, or enough of an aftermarket converter business starts adding pop-tops, the Marco Polo (Vito only, though) has a good chance of making it over here. It would not totally surprise me if a "luxury" package that adds leather, some V-class interior elements, and nicer seats makes it over here for use in the limousine trade. But I would be alone away if a vehicle labeled V250 makes it over here, sold to regular customers, at regular dealers.
Why? Because Mercedes is making a distinct point that the Mercedes-Benz CLA250 is a Mercedes-Benz luxury car, "The Best Or Nothing". And that the Mercedes-Benz Metris is a Mercedes-Benz Van, merely "Born to run." They want the luxury car customers to see the vans as a separate product line, superior to other vans, priced a tad higher than other vans, but just a van. The solid link selling a better equipped Metris van as a Mercedes-Benz Luxury Car minivan has the strong potential to be disastrous. It would have to be an insanely profitable venture.
The Toyota Sienna Super Premium model, the one with those reclining barca loungers, is a bargain. I have ridden in one. It has most of the features you'd think of in a Mercedes-Maybach S600, especially for rear passengers, at a quarter the price. I'm not saying the M-M S600 isn't worth the price, mind. I'm saying that Toyota's Sienna can be equipped as a super luxury car, a limousine nicer than any stretched Lincoln. In fact, Lincoln sells a sort-of luxury minivan in the MKT. Lincoln has never broken 10,000 sales- 4800 last year. Toyota, I doubt has sold more than 10,000 a year of their luxury model (I know they're selling more Siennas, but not the luxury model!)
The Toyota is $47k or so, the Lincoln is $42,500 without dickering. That's oddly close to the price of my Metris without dickering ($40,500). A fully equipped Metris, with very limited luxury (or really, the things most minivan buyers expect to be standard on a base model) would run about $43,500. Given that the V-class would probably come in at... $65-70k? do you really think Mercedes could sell enough V-class models when Lincoln, offering a decent enough product with the features expected of a luxury minivan, can't get the things out the door for $42k?