EDIT: Updated the OP. VGChartz has revised their numbers, from 740k to 580k after the NPD came out.
VGChartz is also clocking in DmC's global sales figures at less than 600k and there are rumors circulating around neoGAF from reputable sources that in the US DmC < 200k, and judging from the ranking of the above image, that's not so far-fetched. With DmC being such a critical success and a commercial failure, it really begs the question - is there simply no place for third person hack and slash games in the industry anymore?
In addition to NG3, DmC's failure is marks the second fall-from-grace from the top dogs of the genre. Both Ninja Gaiden and DMC were heralded as the kings of the hack and slash genre moving into this gen - and with DMC4 being the best selling game in the franchise and Capcom's 11th highest selling game of all time; it begs the question as to why DmC's numbers are so abysmally low. The marketing was fine for the game (bus ads, TV spots, that CG trailer that played in theaters for a solid two months straight, etc) and the release date couldn't have been better. A dry month with no competition, a month before its biggest competitor. It had tons of time and space to breathe and flourish, yet it only manages to sell 3/4ths of a million copies.
The genre has never been about pulling Call of Duty numbers, but with DMC4 pulling 2.7 million copies its fair to say that there is a niche place for it in the consumer base. There are a lot of pieces missing from the puzzle and questions about the future of the franchise, and we're still awaiting a few more numbers to come in (one of them being the DMC HD collection - which is rumored to have sold, ironically enough, around 750k copies as well), but there's no question that a lot of people are getting worried how a good game (and DmC is a great game) could have bombed so miserably. Is the market just not viable for a game like this anymore, or is it no coincidence that NG3 and DmC have now both bombed horribly by turning off the exact fanbase that cultivates the genre by trying to reach out to a wider audience?
I think a lot of publishers, Capcom included, are looking to MGR's reception to see what the future holds for the genre and awaiting its reception with bated breath. If one of the most well known franchises + the most revered hack & slash developer = sales bomb, then stick a fork in the third person hack and slash genre, because it's likely finished... which is a disappointment because they're my favorite genre.
UPDATE: MGR's first week has apparently outsold DmC's first month according to multiple sources, leaving a lot of my previous fears completely unfounded about there not being a market for hack and slash games in this industry anymore.