Sprint’s anticipated Android 2.2 update to the HTC Evo 4G should launch tomorrow and will tote a few surprise additions, a leaked memo  confirmed. The patch will give the expected OS benefits but will also add new camera-focused features with better 720p video and options to use the flash as a flashlight or as a focus assist for movies. A spate of new widgets will also come about, and Engadget’s copy of the note says these will focus on basics like the calculator, FM radio, messages lists and settings.

The 2.2 update will unsurprisingly close a hack that let enthusiasts turn on the Wi-Fi hotspot creation for free by rooting the phone.Anyone getting the update on Friday will be part of a test batch. A wider deployment is expected on August 1 and will be part of a first wave. Sprint hasn’t said how long it will take to finish the majority of upgrades.Update: Sprint has confirmed that the widespread deployment of Android 2.2 will start on August 3.