I can understand some people getting bored with the one track at Thredbo , but personally I havent spent enough time there to get to that point. After one day of riding I'm still getting sections sorted and getting up to speed with the whole course. It would take maybe a solid week up there before I had everything absolutely dialled to the point where boredom became an issue.
That said , I think it would be good to retain the existing track but add some more difficult options to help the bored ones maintain interest. Like having an option to the fire road , its pretty gnarly terrain up there as someone mentioned , I'm sure we've all scoped lines down that rocky outcrop whilst sitting on the lift. Basically keep the current trail as the main route but with a few more options for both beginners and advanced riders. Doing this also spreads the impact of so many riders on the trails over a bigger area and may reduce the amount of trail maintenance overall. Another advantage to this plan is new sections can be added as time permits rather than having to create an entire new trail in one go. (Sure I'd love to see 5 new DH trails up there but lets keep this realistic)
Also last time I rode the fire road in April , the water bars were a bit kicky , even mellowing them a little would be a small but good modification allowing riders to hit them at full speed without fear of going otb at 60ks.
A permanent 4X track seems logical. To me , it's madness building and removing Jacobs' course each time theres a race there. Such a waste...
XC trails : Definately. They may not make as much money as DH but they require less maintenance and expand your target market. All MTB riders , not just DH / 4X.
Thats all that comes to mind right now. Looking forward to my next ride there.