I think one question here is, do we want art that pleases us personally, or do we want art that is going to help the D&D brand to still be a brand ten years from now.
I suspect that most people are most keen on an art style that reflects the time that they were happiest with D&D (not necessarily the first time they met it), or the time they have most nostalgia for. Personally, thus, it'd be "How much money do we need to throw at DiTerlizzi to make him come back?" or perhaps similar with Brom or the like.
I don't think that'd be a good idea for D&D, sadly. The same, I feel, applies to people who want a reversion to '70s or '80s art style. That's not to devalue those style or artists - but you can't go forward by going backwards, and relying on a bunch of aging (and in some cases entirely retired) artists is not smart, I would suggest.
So I think that what we actually need is a highly distinctive and consistent visual style. The "Pixar Fatlings" style was clearly an attempt at this. A failure, I think, but an attempt, and kind of smart/daring one. Using a Chinese computer game concept-art house for a great deal of the illustration might seem cheap or the like, but I think it's smart for this - use expensive Western artists to set the initial look, but then use much lower-cost artists who can largely replicate that style to provide the rest of the art, using the earlier stuff as a reference (I mean, I presume they're doing something like this). The big upside here is consistent art (which will be as distinctive as the original aesthetic, by and large), which makes D&D more marketable as a brand.
The downside, of course, is a lack of variety, and that D&D would no longer be a place to see great art - of course, I think that horse bolted a long time ago - for many years M:tG has been the place for amazing fantasy art, not RPGs, for better or worse.
EDIT - Heresy, I'm sure, but I'd like to go on record and say "character on white background" is not actually a bad thing at all. In many cases such images can be intensely evocative and capable of provoking the imagination in the way that a more rendered scene cannot. You do need a stronger artist, one capable of creating really bold images, to get away with it, but you can get some serious raw power that way (an example of his would be how many of the clan/bloodline/character images in 1E/2E WoD books were B&W character-on-white background, but were ultra-memorable and ultra-distinctive, in large part thanks to Joshua Gabriel Timbrook).