From a visual perspective it's bad. Find yourself a style that looks visually more pleasing than the default vulletin skin.
The logo isn't great and the placement right bang in the middle isn't great either. I would spereate it and implement some space between the bottom of the logo and the top table. Your logo should stand out (which it kinda does) but it's not visually great.
Lastpost icons have a black box which means that it's using another backgrounds matte which should only be applied onto a black background.
Same rule applies to the tcat collapse icons. A black matted set on a blue gradient looks awfull.
If it were me I would revaluate about getting comfortable with this style because there are to many incorrectly saved out images on backgrounds that they shouldn't be applied onto. I would also change the buttons, For me I still class re-coloured (hue and saturated colour shifts) as default and I think you would be doing yourself a favour by replacing them.
Before i forget, I noticed you resized the whats going on icons. Bad move, You may have the psd from the vbulletin gdk but the layers are rasterized and not in vector form so any resizing will reduce the quality.
Goodluck with your forum.
