not bad, but hammer.horror is right - there's definitely issue with the thumb - the stretch of skin that goes from the middle of the main body to the base of the thumb looks like it starts too high. also, in the last image, it really looks like the whole thumb has been pulled out too far and then rotated round too much. it almost looks disjointed.
agree with the thumb issue, but have to add that the fingertips (not the very ends but the all around area of the final knuckle of the finger) looks a little boxy and too long from top of finger to bottom of finger.
SimplyMaya specialises in Maya tutorials. We offer over 1,000 individual Maya training videos, ranging from basic Maya tutorials through to intermediate Maya tutorials. Our tutorials are created by instructors with industry experience and are designed to get you up and running in Maya quickly without making it seem like hard work.