In theory it sounds like a good idea, but there are so many other dedicated console forums out there on the internet I don't really see it a good idea here..
The list of individual consoles would be too large. Not only are there those who like the old school consoles but then you'd have to factor in the next Gen consoles.
You'd also have to consider if each console would get its own forum or if it was done by manufacturer. For example would Nintendo be a subcategory? If so would you also need even more subcategories for each of the products?
And what consoles would be left out? just because a console isn't sold in stores doesn't mean it's retired. There may not be a whole lot of talk about the old systems but from time to time there are new topics started about them. Would the fact that a subcategory such as Atari, that isn't always as active mean that there is no use for that subcategory?
While it would be a great way to categorize each console and possibly reduce redundant questions, it would become a navigation headache.
but that's my $.02