> When APM refers to "Viper" processors on page 15 are they referring to the "Mamba"?

Probably not. Mamba seems to be the first of the three products denoted as "TBA FY2010" at 40 nm. More info of what could be "Viper" was discussed by me there:

https://morph.zone/modules/newbb_plus/viewtopic.php?topic_id=7001&forum=3&post_id=76984#76984