Hmmm, I have a 9650 Bold with the PB charger plugged into the charging cradle. No problems yet, just a phone that charges wicked fast. I figure if it cooks the battery it will be a good excuse for me to go get the 9930 Bold. Been looking for a reason to upgrade.
Side note: I picked up the PB rapid travel charger from Wal-Mart.com for like $14.99 last month or so. That magnetized charging end is great, they should use the same technology on their newer phones. Eliminate the risk of breaking the micro/mini-USB port for charging.