1- Break up your "portfolio" by category or shoot or something ... right now it's just a huge mess of random pictures,
You have pictures of flowers mixed in with animals and portraits ... you should build your portfolio (or portfolios) in terms of the interests of potential clients.
It's also difficult for me to determine what is older and newer so it's difficult for me to tell if you;ve improved.
2- Get a proper website. Facebook does horrible things to your pictures when you upload them.
This is a perfect example of what I am talking about ...
http://www.facebook.com/photo.php?fbid=343086495759689&set=a.343044582430547.76728.272374592830880&type=3&theater
This picture looks like it has tons of digital noise usually created by high ISO but look at your logo ... facebook destroyed it. The noise is far greater because of the processing facebook did to your image when you uploaded it.
Wne uploading pictures to facebook, it's best to resize the images FOR facebook ahead of time instead of letting facebook do it for you to help minimize the ammount of work that facebook needs to do on your images.
Here is a really good post on how to do this.
http://www.robandrewphoto.com/blog/portraits/optimizing-your-photos-for-facebook
3- Your pictures lack contrast ... they all look very blah in terms of color and contrast, they all feel washed out.
This picture is a great example of what I'm talking about.
http://www.facebook.com/photo.php?fbid=344968725571466&set=a.343044582430547.76728.272374592830880&type=3&theater
Here is what it could have looked like:
http://flic.kr/p/c9ghjJ
I had to do this in Photoshop (editing a jpeg and not the RAW is not ideal either) but you could have achieved this in camera.
4- There's no real composition to your shots.
Again, in this leopard shot, what does the negative space at the bottom of the frame bring to the picture?
You might want to pick up a book on composition like:
Photographic Composition by Tom Grill and Mark Scanlon
http://www.amazon.com/Photographic-Composition-Tom-Grill/dp/0817454276
Have I seen improvement in your work? Not really. It looks like you are trying to improve by doing the same thing you did before and that is the path to failure. I strongly suggest you pick up some photography books (Understanding Exposure and Photographic Composition are two great books) and maybe join a photography club.