Looks like it's time for one of my extra long critiques ^_^
While I like the template and it has a lot of potential I believe there's quite a bit of room for improvement. I'll start with anatomy issues from the top and move down and then throws some shading tips at ya .
The one problem I noticed with the head is the placement of the eyes, they're up just one pixel too high which causes them to be right in the center of the head, since you're looking down on the sprite you wanna see a little more of the upper head than the lower head.
Next is the lack of a neck, your body just connects right to the shoulders which isn't how heads are stuck to bodies :P Easily changed by moving a few pixels around ^_^
Down to the arms now! Your main problem here is the shape of your hand, not as noticeable is a few little outline changes pixels that need to be moved for smoothness.
Your hand is gonna have to bump out an extra pixel so that it's defined as a hand and not just an extended part of the arm, making it one pixel thicker on both sides does a nice job fixing this one ^_^ The wrist, however; IS going to just stay straight with the arm, it shouldn't jut in like it is now.
Down to the legs, almost done! I like how you tried to add in the extra detail of knees, the problem is that how is pokes in a pixel looks quite off. Most people's upper legs are larger than their lower legs, sprites should be no exception to that so make his thighs a pixel wider than the rest of his leg, now with the right shading those knees will look great! The feet are last and they're probably the most messed up part of the sprite., but that's okay, a lot of people have trouble with feet at first. I'm really not sure how to explain it, I'd just look at the example I'll have up at the end of this post so you can get an idea of how they should look.
Now that the outlines are nice and perfect you've gotta fix your shading. There's quite a bit of pillow-shading going on here(most noticeably in the arms and legs) and there's lots of unnecessary shading. Getting rid of that though is more of a matter of practice and looking at examples and tutorials to learn where shadows should be.
A little something I did for practice: Take the RTP template and erase all of it's shading. Now re-shade it yourself and compare it to the original. This'll help you learn where you're shading too much and where you're not shading enough! ^_^
Last thing I'd like to address is something that's been mentioned many times already, the side view walk. YES many sprites do show a slight bit of the other side of the body on the side-views to add some detail and make the sprite look less flat, usually they have a slightly diagonal look to them. It's great that you want to add that to your sprite because it's a great idea but the problem is that you made your side views TOO diagonal and now they're in an isometric view. This is something you'll HAVE to change to make this template usable because otherwise it looks like he's strafing or facing forwards and walking sideways.
Hope that helps a bit and here's an example of a small revamp I did! Hope to see some improvement soon, good luck! ^_^
http://img266.imageshack.us/img266/9823/craycritdj5.png[/IMGZOOM]