This is brilliant!
the only suggestion I would have is to make one that uses the same colors as the PS2 / PS3 controllers use for the buttons.
Genius though, seriously.
both these concepts can be trademarked. they are different concepts as the designer pointed out. the "nib" has been used countless times in logo design. If trademarking rights were that narrowly defined as onetreeink implies, the world would have run out of logos about 4 years ago. In my professional opinion theres no problem here. congrats tabs
I love this one :)