Research in Motion announced yesterday at the Mobile World Congress that they will be releasing two more Blackberry Playbook tablets in the second half of this year- one with LTE and one with HSPA and networking technlogy. Maybe this does sorta validate the rumours that Apple is likely to relrease multiple versions of the iPad this year as well. While the Blackberry Playbooks are expected to ship in April/May this year as too the Appe iPad 2, let’s not forget a number of Android-based challengers such as the Motorola Xoom and the newly announced Samsung Galaxy Tab 10.1.