There's no reason to have separate system RAM and VRAM unless they use different types of RAM. Otherwise, it just makes development harder. IGN is really clueless about PC gaming, obviously, and they said nothing about their source saying that it has 512MB of VRAM. Besides that, you can't find 512MB DDR3 anywhere, so if they heard that it was 1GB total (which is what they said they were told), matching it exactly would be impossible anyway. Whether or not they were telling the truth, between the OS overhead and the fact that PCs always have separate RAM and VRAM (ignoring iGPUs, of course), the 512MB of VRAM in the model is probably totally irrelevant to what's in the Wii U.