Skill Focus is normally taken by those trying to max out there skill, but I don't it would also be nice if it could help those that take penalties. Basically your focused training allows you to overcome your innate weaknesses.
The change:
Skill Focus
Benefit: You gain a +3 feat bonus to a single skill. You no longer suffer any penalties to that skill due to ability scores, armor check penalties, or other conditional effects.
So for example, a paladin with skill focus in endurance could now wear full plate and shield but still have a good check.
A rogue could climb a slippery surface with no penalty.
A fighter with a 8 dex could take skill focus in stealth and still be decently sneaky, with no ACP and no penalty from his low dex.
The change:
Skill Focus
Benefit: You gain a +3 feat bonus to a single skill. You no longer suffer any penalties to that skill due to ability scores, armor check penalties, or other conditional effects.
So for example, a paladin with skill focus in endurance could now wear full plate and shield but still have a good check.
A rogue could climb a slippery surface with no penalty.
A fighter with a 8 dex could take skill focus in stealth and still be decently sneaky, with no ACP and no penalty from his low dex.