I was having a maps issue also. I downloaded johnlgalt's maps.zip from post #7 in this thread, unzipped and copied Maps.apk to the sdcard. Then I used these commands in Terminal Emulator:
su
sysrw
mv /system/app/Maps.apk /system/app/Maps.apk.bak
busybox cp /sdcard/Maps.apk /system/app/
sync
reboot
Make sure you capitalize Maps, it matters. After the reboot, I went to the market and chose downloads and the 4.3 update for Maps was there. It installed just fine. My only problem with the new Maps 4.3 is that after every reboot or shutdown, it is like I'm going into maps for the first time and I have to choose the location button from Labs again. Anyone else experience this?