Feel free to disagree with an IP attorney who actually deals with trademark infringement. I guarantee your uninformed opinion won't sway any court.
The issue here is that the names *are* confusingly similar for related goods and services
. In that respect, Blackjack and Blackberry are similar enough to create likelihood of confusion. There are already several reported cases of *actual* confusion, which is strong evidence in a trademark suit. It doesn't matter *who* is confused, because Samsung is the entity that selected the Blackjack name that is leading to confusion.
So, your lay off-the-cuff opinion notwithstanding, there clearly *is* similarity and RIM does have a viable legal basis to bring suit. (Need I remind you of the rights that have been secured for "Mc-anything"?