Google promised that Android 4.4 would be able to run smoothly on low hardware, even smartphones having 512MB of RAM. Google seems to have kept their part of the bargain but sadly, the phone manufacturers don’t seem to be on the same boat though. Samsung already scratched the Galaxy Nexus from the list of devices to get the update. So devices before the Galaxy Nexus do not seem to begetting the update.
Even though the old devices will not get official Android 4.4 KitKat on their devices, customs ROMs are always a possibility. That is the beauty of Android, developers can use the kernel to develop custom ROMs. The Nexus S is one such device which thanks to a XDA member cn.fyodor is getting its own custom Android 4.4 KitKat ROM. The ROM has made the Nexus S relatively faster than before, so Google do seem to be on track of keeping their promise after all.
The ROM is still in alpha stage so it would be having a couple of bugs, but you can do the usual stuff (surf the web, make a call etc) without any hitch, so if you want to have a sweet taste of Android 4.4 KitKat then head over to the XDA link provided below and try it out.
ROM Link : XDA
Note: We at TalkAndroidPhones do not take any responsibility for any issues faced while installing the ROM. So please backup everything and then try it.