CyanogenMod team is currently working on releasing a final build of CM 11 before their start working on the newest Android 5.0 Lollipop OS. Until then we can still test the M12 Snapshot build that's based on Android 4.4.4 KitKat, as it is now rolling out for the Galaxy S, Galaxy S2 I9100G, Galaxy S3 LTE, Galaxy S4 LTE and Galaxy Note 3 LTE models.
It seems like CyanogenMod doesn't want to give up on the original Samsung Galaxy S device, and now they've released a brand new M-Snapshot build for its users to test. The M12 build of CM 11 is a pretty stable release, and you should install it instead of the Nightly builds. If you use the Galaxy S as a secondary device, then the CM 11 M12 release should probably be your default operating system as it is stable and it runs smoother than many custom ROMs.
Besides the Galaxy S and Galaxy S I9000B, we have tons of other Galaxy models getting the new CM 11 M12 Snapshot builds like the Galaxy S I9100G with TI-OMAP chipset, for the LTE versions of Galaxy S4, Galaxy S3 US and Note 3, as well as for the Samsung Epic 4G, Galaxy S2 Epic Touch 4G, and the Captivate model. More Samsung devices should get the new CM 11 M12 build before the end of this month, so you should keep an eye on CyanogenMod's Download page in order to learn first when such builds are made available for download.
In order to install such files on your device you should use a custom Recovery such as CWM or TWRP. Download the ROM zip file, and the Gapps zip, move both files to your device's internal storage and then flash them using the custom Recovery image. Note that in order to correctly install the CM 11 M12 builds, then you should make sure to apply a 'factory reset' first. More info on how to install such custom ROMs can be found in our Update section, find your device, use the CyanogenMod download link and follow the instructions listed in our tutorials in order to complete installation.