The choice between shiny new CM10 and good ol' CM7 isn't a tough one for Defy users, it's a matter of priority: adventure vs stability. But once you've tried JellyBean and it's lovely UI, going back to GingerBread is a pain to the senses! That doesn't takes away from the fact the latest CM7.2 is amazingly smooth so only the UI needs bit of tweaking and theming.
Enough talk, here's what this thread is about. Screens taken from my MB525 on maniac103's CM7.2 -
Description -
Mods:
--> JellyBean style notification layout & icon, clear button and botttom carrier name (thanks to
AChep. His
thread)
--> JellyBean style notification bar date and settings button (thanks to
petrukgrinder. His
thread)
--> ICS style settings (thanks to
balamu96m. His
thread) with fixed redundant entries and graphical battery info on main screen
--> Roboto fonts from CM10
Theme:
--> Holo style theme for ThemeChooser. It's a fixed version of
jasonevil's Ice9 theme. Updated resources and color schemes to be more like JB, custom icons, Nexus 4 analog clock, improved XMLs etc. In fact so many changes have been made that I renamed it Ice10 so you can install it alongside with the original one.
Instructions -
--> To keep things simple I have just included the tweaked files in a flashable zip and the theme as installable apk
--> Download the mods for your build (see
Important section below if your's is not listed):
JBMakeOver_MB525_maniac103.zip (2510)
JBMakeOver_MB526_maniac103 (0711)
JBMakeOver_MB526_Fuzz (2611)
--> Download
Font.zip
--> Go to recovery, wipe dalvik and wipe cache
--> Flash the zips and reboot
--> Install
Ice10.apk, apply in theme chooser and reboot
--> Recommended install:
Holo Launcher
--> Done
Important -
The tweaked files in the zip (fremework-res, systemUI, settings, deskclock, bluetooth, phone, music and downloadprovider) are verified to be working on my MB525 with maniac103's build. In theory, they should work with any CM7.2 build but I haven't tried with others. I won't/can't download a whole ROM on my slow network so people who are facing problem with their preferred builds (Official, Fuzz's or Epsylon3's) MUST upload these system files and I'll patch and include them here.
Before trying, always create an Undo.zip by replacing the respective files in the mod with yours.
The theme however is universal and will work for any device so if you don't want the mods, just use the theme 
Same goes for fonts.
Otherwise,
Make your own mod (you must know how to de/re-compile an apk) :
--> Download
ACPatcher and the ICS notification bar patches from
here (thanks to
zhuhang and his
post)
--> Copy the necessary system files into the res folder of ACPatcher, run patcher and follow the onscreen instruction
--> Your zip will be created. Don't use it yet.
--> De-compile them for furthur (JB specific) modding.
--> Now just follow the instructions in
JBMakeOver_Changes zip which contains the files to be changed/added to make your own mods.
UPDATE: 23rd Nov 2012
--> More JB like notification bar (See updated screens) with settings button
--> Battery text in status bar made smaller for better aesthetics. Also battery bar (maniac specific) displays properly now.
--> Settings.apk tweaked with more logical groupings.
--> Theme update
UPDATE: 28rd Nov 2012
--> Added support for 0711 maniac103's
MB526 build:
JBMakeOver_MB526_maniac103
--> Added JB transition animation
UPDATE: 30th Nov 2012
--> Added support for 2611 Fuzz's
MB526 build:
JBMakeOver_MB526_Fuzz
--> JB transition not included in this build as it's incomplete. Switched to ICS animations. Will also be removed from other builds in future updates.
--> Theme update.