The official Steam page for Watch Dogs is finally up, and it brings with it the official minimum and recommended specifications you'll need to run it, direct from Ubisoft.
To get the game up and running at all you'll need a 64-bit operating system -- Windows Vista, 7 or 8. Processor-wise, you'll need an Intel Core 2 Quad Q8400 or AMD Phenom II X4 940 as a minimum, along with 6GB RAM. The game will take 25GB of hard drive space, and on the graphics front, you'll need a DirectX 11-compatible graphics card with 1GB of VRAM. Both Nvidia and AMD cards are supported.
If you want the game to look its best, meanwhile -- that is, up to (and possibly exceeding?) the standard of the recent "Welcome to Chicago" video (above), which was recorded on a PS4 devkit -- you'll need to beef things up a bit. An eight-core processor is recommended, as is 8GB of RAM and a 2GB video card, but your reward will be enhanced lighting, water, wind and other weather effects.
The Internet doesn't seem to quite know what to make of recent Watch Dogs footage, as it has been somewhat variable in quality across the various different trailers that have trickled out over the course of the last year or so. This is perhaps to be expected of a game that is awkwardly straddling two generations of hardware -- the game's lofty ambitions of an interconnected open world that you can fiddle with to your heart's content represents a vision perhaps best realized on a new generation system or powerful PC, and yet it's still coming to the more dated hardware of Xbox 360, PS3 and Wii U, too.
On May 27, we'll find out whether Ubisoft has successfully managed to realize that vision across all the platforms the game will be available on. In the meantime, you can preorder the game for PC here.