I can't say I really know the answer to this question as none of my articles reached the front page, and I don't think they will ever be there mainly because digg audience doesn't care much about the type of content I write, but check out this site www.venturecake.com.
The site has only 11 articles and 6 of them reached the front page on digg.com. Venturecake.com is a blog about technology, mainly open source, Linux, Unix, Apple, and some others. The last post ( Who copied who? ) was published yesterday and it got over 600 diggs in one day.
The posts that made it to digg's front page are about common buzz words like Apple, Web 2.0, ( Web 2.0 is built on Open Source ), Open Source ( yes this is still a buzz word ), Ubuntu and Virtualization ( 15 minutes to using your existing Windows install & apps in Ubuntu , 10 minutes to run every Windows app on your Ubuntu desktop ) but also some unique tips like
10 Linux shell tricks you don’t already know. Really, we swear.