I have received confirmation from Sprint that there is 1 exception to this new data plan.
If you have a smartphone that was originally activated prior to 1/31/11, and the device is replaced under warranty or insurance, then the $10 charge does NOT apply.
My son found the exception here in the Sprint Community pages:
Sprint Community: Plans: What's there to know about the $10 Smartphone Premium Data Add-on?
...and Sprint confirmed it for me.