Many of these designs use italics in the main text area. While I don't think the slashdot site has poor readability currently, a new design relying on italics will seriously compromise the attention and enjoyment of your readers.

I invite you to consider the example of the NY Times website which has recently undergone a redesign. One of the striking aspects of the facelift was the font change. The new fonts were obviously carefully selected in terms of typeface, size, spacing, kerning, etc. The new site was designed specifically for the screen and is a pleasure to read on any screen.

While I am not a design professional by any stretch, I would urge you to consult a few freely available resources on web design, especially accessible web design for the visually impaired.