Not sure he will be getting this every year. The first 50% vests in 5 years and the next 50% vests 5 years after. This seems like a large deferred bonus to encourage Cook to maintain or increase the stock price for the long term.
I read that as the 380 million in 10 years deferred CEO bonus, in addition to his current 60 million/year total compensation, would total to around 1 billion at the end of 10 years. I'm going to go out on a limb and guess it will be well north of 1 billion, once stock price appreciation is accounted for. Hope he considers taking the http://givingpledge.org/ :)
RSUs are fairly standard as a bonus inside Apple (not this many though!). Typically, they vest over four years, twice a year as long as you stay an Apple employee.