Several sources have apparently told BGR that the RIM PlayBook will launch on April 10th in retail locations (US only, I presume).
The Playbook OS will only be finalized on March 31st. As a result, users will be prompted to upgrade the first time that they boot the PlayBook.
RIM has yet to disclose pricing but last month, a leaked document suggested that the 16GB Wi-Fi-only PlayBook will sell for US$499.