OmniFocus 2.0 came out just about 2 weeks ago and it's been such a nice update so far! I think there are still a few things to tweak by the Omnigroup over the coming months; Namely the ability to move the checkmark over to the left, next to the start of the item / list.
If you're looking to customize it a bit, here are 2 little things I've already done to my setup!
Customized your Perspective Icons
Check out these icons by Josh Hughes and use them instead of some of the default perspective icons (and make your own perspectives with them in the pro version!)
Customize your sidebar
If you head into the Perspectives tab > show perspectives if you click on the star next to a perspective, it will appear in your sidebar.
Pretty easy! You can also edit the perspective icons in this window as well.