From what I've been told from the mobility staff, there are more places available for exchange than there are applications. So they'll look at your average over all units that you've completed (regardless of first year, second year), and if that works out to be 65% or more, you're eligible to go on exchange (as long as you meet the other requirements too). They have said that 65% is enough for you to go on exchange at least somewhere. To get into a more popular university, or one of the 'better' universities, you will need higher than 65% and this will vary with each intake.
I reckon you should still apply for exchange right now - it will mean that you will be studying overseas in semester 2 next year. It's a lot easier to study elective or breadth subjects in the partner universities, than it is to study subjects for your major (which might be the case if you send in an application next year). Major subjects have to be pretty much identical and equivalent to a major subject at UoM. You have until the 6th to submit it!
Hope this makes sense haha.
I really want to go to King's College or University College London or Queen Mary though which are going to require an average of 80 to be competitive, since London is quite popular and there aren't too many place. Which isn't impossible considering my grades from this year but it's very possibly I'm underrestimating the difficulty of the task haha. Hopefully if I can do really well in second year but I'm still just under 80 or just barely above they'll forgive my first year slacking. #wishfulthinking
This being said I've always found oddly that when I miss out on something and am forced to take an alternative route, the alternative turns out to be a better option, so we'll see!
Originally I was planning on going on exchange second semester of my second year, but since I'm planning on extending my bachelor course to four years (studying part-time in the fourth and working near full-time) anyway I've decided it'll be much better if I save up the money and go during the second semester of my third year and hopefully have a better experience. There are quite a few extra-curricular things I want to do in Melbourne next year, plus a bunch of second year subjects I really want to do at UoM.
I'm planning on taking three electives on exchange anyway (according to my current course structure) and only one major subject. I've already spoken to the English coordinator and he said it should be relatively easy to credit it to my BA. If not, I'll come back and do it in my fourth year.