According to a post by David van Tonder earlier this evening, CyanogenMod's 4.3-based 10.2 iteration will be able to boast a "Global Blacklist" among its features.
CyanogenMod is known for its subtle yet incredibly useful additions and tweaks to stock Android, and the new Blacklist will blend right in with a "holo compliant interface".
As the name implies, the blacklist will be truly global – it will support blocking of calls and messages, will be configurable through Settings, Phone, and Messaging, and available to third-party apps via a "new Content Provider API".
Users can enter blacklisted numbers from their address book (the People app) and even block numbers with wildcards, or those that are unknown and/or private.
Besides that, the blacklist makes blocking unwanted calls and messages exceedingly easy – blacklisting options will appear on the in-call screen, call history, quick reply popups, and the Messaging app's conversation view.
As always, you shouldn't expect an ETA from the CM team, but it's great to hear that 10.2 will pack in some great new features.