Ryan Petrich has announced a public beta of Curiosa to provide notifications and background updates for Cydia.
You can choose to have Curiosa to update hourly, every two hours, every six hours, daily, manually, or after respring. A manual refresh can be performed using Activator Events.
Curiosa will show update notifications for packages that are installed and those that match the specified keywords.
You can download and install Curiosa from the http://rpetri.ch/repo beta repository.