Lucky for you... I'm from both states... lived in IL all my life recently moved to CA... anyways... weather - can get quite cold in the the winter... you'll be spending a majority of your school year in the cold weather so you'll get use to it quick... in the winter you'll have to warm up your car, which is always a pain... and if it snows your in for a treat... lol... nothin' to worry about that you'll get use to it fast...
traffic - nothing you can't handle if your from cali... traffic ain't bad... but don't be expecting to go 80mph as u are in cali... there's cops everywhere...
1st year - I'm class of 2012... and we are the guinea pigs for the new curriculum... 1st year is a not very difficult, it'll definitely be a bit different in terms of exam schedules (2 exams every week or so...) a lot of classes will be repeats of what you took in college...
2nd year - this is what i think of it...
... I've never experience such hardships... lol.. they have honestly bombarded us w/ the toughest classes and exam schedule I have ever seen... no worries they are changing it somewhat for you guys...
hope that helps...