Rumors surfaced yesterday on TechCrunch of a possible retail release of the BlackBerry Curve 8520. The long-awaited device features optical trackpad navigation to replace the BlackBerry’s traditional trackball.

A slide showing off the new BlackBerry device suggests an Aug. 5 retail release at all T-Mobile locations. According to the slide, the new Curve 8520 features a form factor similar to that of the BlackBerry Storm and will include all the usual features, including qwerty keyboard. The device also will be enabled with Wi-Fi.

The slide, presumably leaked from T-Mobile, states that the new device is “an exciting entry-level addition to T-Mobile’s BlackBerry line-up and will replace the BlackBerry Curve 8320.” There was no mention of a launch price.

Research In Motion (RIM) recently released the BlackBerry Tour on Sprint and Verizon’s networks.