png transparency does not work in one of the IE browsers, 6 if i recall.
the hack to make it work is just not worth it, even with a DOM. That would make the isolated alpha png as a working solution for all browsers useless, unless it was collapsed into graphics and used in jpg or gif graphical areas. I can see your just transferring it so thats ok.
matt rock, when a button or graphical element is too large, it screams newbie graphics.
Try to reduce your elements to about 50% of what i can see above, while still retaining the crisp sharpness. Try not to overload your critical navigation areas with fluffy backgrounds, making the navigation text harder to read.
Check out some navigation articles on the internet, its a full blown subject they pay a lot of money for in marketing design etc..
Rely on CSS to manage a style of link, creating new graphics for each button state is very old school and not really performed any more in the real world of web design.
create a background for one and you have a background for all.
Build a style that makes the textual data in the link appear to have mouse states.
The photo in the template that Phaelax posted, by higgins appears to be stretched and blurred. Not very clear or crisp as your main focal graphical point. The screenshot window is rounded and the rest is not, stick to one method so there is continuity across your whole site, the fonts vary as well, stick to 1-2 fonts for the whole site.
The design is also developed or presented at 840 pixels. This width is not standard to start slicing it.
A lot has not been factored in with the elements posted above. but it appears your doing ok with progress, there is still a way to go before I would give it any praise however, and as much as you will get from web design forums.