The 10g track may not be available for several months. The beta exams have not been announced yet and the track is not usually finalized for about 3 months after the beta exams close. So it migh be a long wait.
Also woth considering is tha fact that racle9i will be around for quite some time. There are still plenty of people who are in the process of migrating from 8i to 9i now.
In your position I would definitely do the 9i track then the upgrade exam once it's released.