If you are considering to buying an iPad... maybe you should stop and consider the upcoming tablet computer by BlackBerry maker Research In Motion Ltd.

RIM will unveils its new tablet computer with 7 inch screen and new operating system on next week at a developers' conference in San Francisco. Currently, the Blackberry tablet is known as BlackPad. It is scheduled for release in the Q4 of this year. It will feature one or two built-in cameras too.

According to the people who've worked on the new OS. They say it's a worthy competitor to Apple's and Google's platforms, and could go a long way toward addressing complaints that RIM's devices are slow, unstable and hard to program for.

By time, when RIM is ready for announcements and product demonstrations, probably I will have more details on the features of the new BlackPad as well as the new OS.

Check out the table of some existing and upcoming tablet computers after the jump.