Dagmar
Defender of the Bunnies of Skyrim
VG Chartz isn't particularly reliable. While most of their figures have about a 10% margin of error, the variance is such that specific instances can and have exceeded 25%.I found the following unit sales numbers for Skyrim by platform (as of 3/9/13) on the site VGChartz.com. I make no claims about their accuracy, but they seem in the ballpark.
The reality of the matter is there is no reliable public source to track game sales on a global level. Game publishers may put out statistics periodically but they stop doing so once game is no longer a top seller. This can result in a significant margin of error as a game ages out from its release date even when more reputable research firms like NPD Group provide the sales statistics. The sales statistics are also geographically restricted. NPD Group is probably the largest provider for retail sales statistics for video games and its data only covers the United States, United Kingdom and Japan.
That being said one doesn't need reliable global sales statistics to realize that that game console market is a significant part of the consumer market for video games. According to information published by NPD Group, for the year 2012 in the United States alone $6.71 billion out of $7.09 billion in video game software sales were for non-PC video game software. There's no way we can extrapolate that into even soft numbers for Skyrim across the three gaming platforms, but even if we assumed a 50% margin of error for less reliable sources like VG Chartz that's still a game console consumer market of roughly 5 million for Bethesda's Elder Scrolls game series. It's highly improbable that Bethesda is going to abandon development of games for such a large portion of its consumer base.