In my opnion SIMBIN needs to decide what public they want to reach, becaus eif they try to get the arcade fans and the simulator fans (as they have done with the Race series) they will loose both sides. To me the only option SIMBIN have is focusing in the Sim Racers with an improved version of GTR2... if they go to the race series again sim racers will go to rF2 and arcarde fans will go to F1 2010 and GT5.
I really don't agree with your simple simulation/arcade classification. The reality is way more complicated than this. How can you put GT5 in the same category as Mario Carts? F1 2010 isn't out yet so its hard to say just how good a sim it is, but it will simulate many aspects of racing far better rFactor or iRacing.
I also think you have over-simplified the buyers of racing games. You can't put them into two categories - there is cross-over - I own a variety of racing games and if you visit Amazon and select a tradtional racing sim you will see that people who bought this also bought less serious racing titles.
I found my first on-line racing experience with GT Legends very enlightening as to the sort of people who really buy racing "sims". I won one of the early races because I was the only person who could keep a Mini on the track for three laps. I tried a 10 lap race with about 16 on the grid - by lap three there were only four of us still racing.