Personally I can see why they went for a time trial as the frist eliminator - it can demonstrate those people who have basic speed. Its the only fair way to do this as any sort of online race would just degenerate into a punting contest which is my biggest frustration with the game. To an extent it doesnt matter if the guy behind you is faster, he is still behind you and it is his or her job to make a safe pass, which one the whole doesnt happen. I also note the points made about racing fast and being fast on a time attack type event to be completely different. It is possible to post a fast lap on time attack for one lap - but then try to keep that up for 50 laps, continuously, with other cars around. It just doesnt compare.
I have some real world racing experience (okay Karting) but it can be a very stressful place. I always remembered my heart racing away at about 200bpm (think the pre-start sequence in the movie 'Le Mans') before the starts, especially when I knew I was in for a close race or the final. The other thing that is very real is the risk of error. For example, most people get on the gas in the game regardless of a car in front of them. In real life you just wouldn't do this, you would wait for the car in front to do this first, which gives them a few yards and the ability to hold you off for the length of a straight, and if you did do it you would almost certainly get black flagged.
I cant remember where it was posted (but it has already been posted in another thread), but the fastest line round the track for a time attack is different to that for a race. If you brake and aim for a late apex when in a race, you are effectively 'leaving the door open' and you can be pretty sure that when you get to the apex, you will have another car on the inside of you as you haven't protected the corner. Driving a 'protective' (by that I mean minor adjustment to the racing line to prevent handing easy oppotunities to a following driver - not blocking) line can often mean that you can keep someone behind you who is two seconds a lap quicker.
Anyway. I will be entering, I dont know how I will do, but in the tuned Suzuki Cappucino on the Eiger track in the GT demo, I was usually ranking reasonably well, but I dont have any idea of how many people played that game compared to the GT prologue (then again I havent really tried time trialling on prologue). Either way, it will be fun. best of luck to everyone.