You simply cannot compare it to any traditional screen setup.
The optics of the Rift focus more pixels to the center of your vision, so it looks more clear in the center than the periphery, just like real life.
Just watch the videos like these ones, they give you a pretty good idea of what kind of quality you get in the Rift.
In this video skip forward to about 1:30:
http://www.youtube.com/watch?v=OKwA_wDO3o0
That's pretty much what you see in the current dev kit, it's not blurry at all, not in the traditional sense. The problem is currently there just simply aren't enough pixels to display enough information to see in the distance, so people thinks it looks "blurry" but it doesn't. The picture is perfectly clear, but the screen door effect makes it look worse than it actually is.
Here's a video of the 1080p prototype with iRacing, not as in-depth, but gives you a decent comparison.
http://www.youtube.com/watch?v=c9RsgsdqQQA
You can easily see in this one that the 1080p is a huge jump in detail. You can see much further into the distance. Things look more detailed and clear close up and far away.
Clearly the more resolution we can get the better, but I think if the consumer version comes with a 1080p screen it will be just fine for racing. I'm using the 1280x800 dev kit for racing and all it takes is knowing the track well. Like I said, I enter races with it 6 or 7 times a week but I test and practice driving with it even more often. 1920x1200 or even 1920x1080 is a significant jump in overall pixels over 1280x800 so in my opinion it will be fine.