1. Download MMS.apk from below
2. Move to SD Card
3. ***Backup Touchwiz Messaging App "SecMMS.apk"*** by renaming the file to "SecMMS.apk.bak"
4. Move the downloaded MMS.apk to system/app
5. Fix Permissions to rw-r-r
7. Hit your dougie or other victory dance of your choosing
I've attached screenshots to show that this is indeed working. The ROM I tried it on is incubus' JellyWiz RLS7 but it should work on any rom. I'm not responsible if you brick your phone or mess up your messaging app but it's pretty straight forward! If you're scared, go to church... or just nandroid
This is my first "helpful" post so if it's in the wrong section or if I've done something else that may cause WWIII than just let me know and I will fix it. I didn't see any other threads like this one though!
Edit: Didn't test thoroughly enough and as other users have pointed out, it FC's when trying to send or receive a picture message. Still, for someone who likes the quick reply, emoji, look and feel of AOSP, I think that it's a small price to pay. Also, this will ONLY work on Jelly Bean Roms!