Mac.AppStorm isn't an app catalog, but it is a great resource for Mac software information and reviews.
Update tools: I mentioned that Bodega offers some automatic update capabilities, but there are a number of tools that can constantly track your installed Mac software (commercial, shareware and free/open source) and alert you to updates. Some of the better options include MacUpdate Desktop, AppFresh and MacKeeper. MacUpdate Desktop and AppFresh are free and focus just on update management, while MacKeeper is a $38 tool that offers a range of other Mac utility features including antivirus protection, backup, file encryption and disk space management tools.
Finally, another potential alternative to Apple's Mac App Store is brewing. Cydia, the unofficial app store for jailbroken iOS devices and apps not approved by Apple, has announced plans to create Cydia for Mac. The exact purpose of creating the store is a little unclear, since Mac OS X will remain an open platform where users can install any apps they want (no jailbreaking required), but once up and running, it will offer users an additional storefront-style option.
The tools in this list may fall short of what's coming in Mac OS X Lion, but they do approximate some of the Lion features we've glimpsed. Some offer advantages that we may not see in Lion, such as character-based gestures and the ability to fully customize individual Spaces. Regardless of how they compare to the upcoming Lion, they offer great benefits to Mac users in the here and now.
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