Research In Motion Co-CEO Mike Lazaridis on Thursday revealed that the 4G versions of RIM’s PlayBook tablets will not launch this summer, as the company had previously announced. The delays were mentioned in passing as Lazaridis mentioned how excited he was to be launching 4G PlayBook models this fall. RIM had previously stated that three 4G versions of its PlayBook — an LTE model for Verizon Wireless, a WiMAX model for Sprint, and an HSPA+ model for AT&T — would launch this summer. RIM also noted that the new BlackBerry Bold 9900 / 9930 would be delayed until the end of August. Like the 4G PlayBooks, RIM has said previously that the new Bold would launch this summer.