According to http://www.blackberry.com/btsc/dynamickc.do?externalId=KB17984&sliceID=2&command=show&forward=nonthr..., OS 5.0 will be available on the Curve 8330. Will Sprint offer this once it's released?
RIM will provide to All of the phone companies, and then the company will distribute. Rumor has it that it will be available 10/28/09
And that would be tomorrow....