I'm living in Hong-Kong, most local banks now offer to open CNY-denominated saving accounts.
Unfortunately I believe the max amount you can deposit is 10,000 CNY. Unless this changed recently.
Contact your local HSBC branch, may be they're offering CNY saving account in the US too, I guess your CNY-saving account would be opened out of HK.
I personally don't speculate on the appreciation of the CNY because (1) my personal opinion is that it's still going to take a long time before a reevaluation of the CNY, and (2) reevaluation is unlikely to be very big at the beginning, we're talking about less than 5% here.
I, again personally, think the potential return isn't that great.