From what I can gather our grade wasn't smarter, it was just that the scaling for the HSC marks was such that there were more band 6's than previous years, and this was because people were complaining that there weren't enough band 6's. The end result is that there are less 88's/89's and more 90's/91's, and while it appears our year was more successful it is really just an artificial inflation of the marks to make it look this way. Given that the UAI is a rank based off the raw exam and assessment marks (the UAC scales them again) then it will not have been affected by the HSC marks which were scaled by the Board of Studies (ie moderated marks, not raw marks). The only thing that could have changed is if you tried to calculated your UAI off the HSC marks, then (in a perfect world where each subject saw the same increase in band 6's) if you got 90 in every subject in the 2007 HSC your UAI would be equivilent to the UAI you would receive if you got 89 in every subject in the 2006 HSC.
Therefore, if your ability remains the same in each subject you should get the same UAI year to year, even if your HSC marks appear to change due to the Board's scaling process. This is not entirely true, as the number of candidates in each subject changes each year, and the UAI is a rank which takes into account student and subject rank, therefore it will flucuate, but if you take the subjects which have consistant scaling and numbers of candidates then your UAI will remain roughly the same.
That said, the entry cutoff for university is not based on UAI, but on the number of places together, the cutoff is equal to the UAI of the last student to get in (eg if a course had 100 places the UAI cutoff would be equivilent to the UAI of the 100th student, meaning that had a student had a higher UAI to the cutoff and had applied to the course they would have gotten in, with some exceptions). For many courses the UAI remains relatively the same, that means that the same number of candidates apply for it and the UAI's of the lowest ranked candidates remains roughly consistent over time. There are only three ways for the UAI cutoff of a course to change:
*If the course suddenly becomes more or less popular, in which case the UAI will increase or decrease to align itself with the lowest ranked student who was successful in gaining admission
*If the number of places in a course changes, in which case the UAI will increase/decrease as more/less people gain admission (still aligning itself with the lowest ranked student)
*If the number of students sitting the HSC drastically changes, as the UAI is a rank this means more people would sit on each UAI point (eg 40 people get 80.05 instead of 25), this means that if a course has 100 places these will be filled by the top 100 students who apply, as there are more students with a higher UAI (in the example of more students sitting the HSC) then the cutoff will appear to rise (assuming that the proportion and rank of students applying for that course out of the entire student body remains the same)
I'm really just rambling now, the end result is that the scaled HSC marks (which are what give us the band 6's and hence make us appear smarter) will have no impact on the UAI cutoff for courses.