A bucket-load of community data, Facebook-styled "like" and "dislike" of user comments, and a pile of interface tweaks that make the program easier to use capstone SlimCleaner 2.0 (download), available exclusively today from Download.com.
The update to its sophomore version makes some big changes from version 1.6's collection of robust tools. There's a registry cleaner, for sweeping up all the detritus left by unruly programs after you uninstall them, a faster scanning engine, and recommendations for similar programs. The recommendation engine appears to be accurate, so if you're looking at Adobe Reader, you'll see suggestions on the right for Foxit Reader, Nitro Reader, Sumatra PDF, Nuance PDF, and a button at the bottom to view more suggestions.
At first glance, the interface changes won't be that apparent. The program has the same layout and uses the same candy-colored ratings system. However, the list of tools on the left nav have been reworked, so that there's now a section for browsers, and the main windows have been tweaked so that you won't need a scroll bar to see all of them.
I still think that its a tool for power users, or at least for people who want to control more about their computer's behavior. This isn't a simple, "set-it-and-forget-it" utility, even if it does have those options. Nevertheless, that doesn't mean it's not a bad tool, and clearly from the growth in user contributions, many people have found it to help them clean and maintain their computers.