There is a new app available in Cydia called FlowDock and like its name suggests, it brings coverflow style to your dock icons. It looks pretty nice but there are a few restrictions. First you need to have 5 apps in your dock. And second, these apps have to be Safari, mail, phone, iPod, and SMS. Once downloaded from Cydia, you need to activate it in WinterBoard.
Here is a picture, compliment of iSpazio. If you installed FlowDock, tell us what you think about this app in the comments.