I think we need to move to a post results application system. If Unis started their courses in January, this would definitely be workable. People would need to apply to less places (maybe allow 3 choices per student?) as they wouldn't need an insurance and would have a good idea of where to pitch themselves- so processing could be a bit quicker. This would still allow plenty of time for interviews for courses that want them.
Having six months between the end of A-levels and the beginning of uni would give people a chance to do something positive as well- e.g. a job, an internship, traveling, something like NCS.
It would also be easier to sort out accommodation etc if you definitely knew where you were going a few months in advance.
In the current system with most students now not sitting proper AS exams, I think it's hard for everyone. Some students will miss out. Some will overachieve, many will have lots of stress between exams and results day. It's also pretty hard for unis- I'm sure the current system isn't working ideally for them, and there's a lot of chopping and changing on results day now.
However, A-level study is different to GCSEs, so unis do need some indication of how a student might perform at A-level. Personally, when everyone was declaring their AS grades, I think this was a much more workable system. It forced people to be a bit realistic with their choices and unis could see if a school had massively inflated their predictions.