Remapping "Command + Arrow Key" to jump through the words of CamelCase expressions?
⌃← and ⌃→ do that by default in many code editors like Xcode, TextMate, Sublime Text, and BBEdit. (If you have disabled the shortcuts for changing desktops.) You can change the shortcuts in TextMate by overriding KeyBindings.dict.

I have tried adding something like this to DefaultKeyBinding.dict:

"^\UF702" = moveSubWordLeft:; // control-left
"^\UF703" = moveSubWordRight:; // control-right


It doesn't work in other applications though. And ⌘← and ⌘→ can't even be reassigned in DefaultKeyBinding.dict.