Steve Jobs announced yesterday that iPad sales had risen to at least 450,000 units, and iBookstore downloads (not sales, as the paper of record had it) reached 600,000 books. Jobs also presented Apple’s new iPhone OS 4, available this summer. As hoped for, the company will bring the iBookstore and iBooks to iPhones and iPod Touches as part of the updated operating system. Like other reader apps, that move will allow consumers to read (and sync) their iBooks across iPhones, iPod Touches and iPads.