What will happen on August 7, 2007 will be the release of the new iMac models, NOT new iPod model releases.
The new iPods will probably arrive around September 18, 2007. It will be available with these new models:
iPod nano--no hardware changes, but 2 GB model dropped, 4 GB model becomes low-end model, 8 GB model becomes "mainstream" model with cases in up to 12 different colors, and new 16 GB model. I think people forget most people want portable music players to play audio, not play videos.
iPod video--new 6G model that has the same physical size as the 5.5G 80 GB model (to maintain compatibility with current iPod docks), but now sports a full touch screen with either iPhone style or Click Wheel style controls. The touchscreen will be a 8:5 aspect display with the same resolution as the iPhone (320x480). There will be NO WiFi capability, but will have Bluetooth connectivity for use with wireless headsets and connection to car stereos with Bluetooth connectivity. Storage capacity will be 60 GB and 100 GB hard drive initially, and probably by Spring 2008 a a version with 32 GB flash memory.