The update is apparently a day one update and is just for bug fixes. I've been playing since Friday! Took an hour last night and cos I'm on the second to last mission I had to wait for the whole thing to install. :-(
Finished the PC version and thought it was a blast to play. I'm currently on a second playthrough with the alternate timeline. I'd give the experience an 8.5/10.
The reason why Wolfenstein looks dated is the id Tech 5 engine - it's nothing to do with the 360 and PS3 versions! Part of the deal between Machine Games and ID in order for Machine Games to make another Wolfenstein game; it's all in a Reddit Ask Me Anything that one of the dev team did