At the moment its just a list of threads which you can search through.
I think general CV/cover letter advice should definitely be a sticky. There are far too many people who start new threads for these when they could have a sticky as their first port of call and then if they need more specific advice then they post in the subject areas- my next suggestion.
The only categories I could see are in the top right hand corner which splits threads into Phd, Masters and off topic.
I think it would be really helpful if there were also breakdowns for different topic- There don't have to be many. It could be something like
-Natural/health sciences
-Engineering/IT
-Arts
-Humanities.
Finally a section for non academic stuff- because people do post about topics such as relationships, work/life balance, money etc. For example if I want to (and I will shortly as Im due to begin in October) start a thread on accomodation, then after a few days of no activity, the thread will go on to the second page and wont be seen as often.
I'm not one for change for change sake, so I really I think these could reduce the duplication of topics, and make it easier to find the relevant topics