You can see the localization strings for "iSight HD" by opening the following file in either QuickLook (space bar) or by opening it in TextEdit: /System/Library/QuickTime/QuickTimeUSBVDCDigitizer.component/Contents/Resources/English.lproj/Localizable.strings
Once you have the file opened, you can clearly see where Apple has placed the following bit of code:
/* Next Generation USB iSight */
"iSight HD" = "iSight HD";
We should note that while this code has been found, it doesn't necessarily mean that Apple will release a new iSight product, but this does give us hope.
[via World of Apple]