Bits and pieces of what we can expect with CM10.2 are being revealed little by little and as of today it looks like we have yet another piece of the puzzle. The latest details are coming by way of the CyanogenMod Google+ page where they are talking about a "Global Blacklist." Basically, it looks like CM users will be able to block incoming calls and/or text messages with v10.2.
As we always see from the CyanogenMod team, there hasn't been any sort of timeline given as to when this would be available. For now they have said the hardware maintainers are bringing up the device repos and other members of the team are continuing to improve the feature-set. What they have offered though -- is a list of the core features for the blacklist.
You can get a brief look at the setup of the blacklist from the images included here in the post. The blacklist will be within the Security Settings, App Security. It will be available to third party apps by way of a new Content Provider API and it is said to have a Holo compliant interface.
More to the point here, the blacklist will support wildcards as well as the blocking of both private and unknown numbers. You can put the blocks in place by choosing an entry in the People (address book) or by manually entering them. They can also be blocked from the in-call screen, call history screen, quick reply popup and the conversation screen in the messaging app. Basically, you shouldn't have any trouble blocking numbers.
Otherwise, number blocks can be set for incoming calls and/or messages -- or both. Finally, there will also be a whitelist option as well as an option to unblock a number by way of the display notifications. But in the end, what this means is yet another solid built-in feature that will be available for CyanogenMod users.