If I am not mistaken you can use the Lion recovery partition to do an archive and install which might resolve the issue for you.
Thanks.
Suggestions that have worked for the 10.7.3 CUI problem include:
All fixes involve downloading the 10.7.3 combo update from Apple and installing that over the failed 10.7.3 update.
1. If firewire is available, boot another Lion machine, connect to failing machine via target disk mode, run combo installer pointing to failing machine disk drive.
2. If you have an external disk drive, can install Lion on it, download combo installer, run combo installer pointing to failing machine disk drive.
3. Same if you have Lion on USB stick.
4. If no firewire, no external drive, no USB installation, least destroying seems to be to use recovery mode (boot with Command-R), then reinstall Lion. This may install 10.7.3 directly. If not, can download the combo installer and update.
5. Last resort which many people are doing is to restore from a Time Machine backup if available. Can decide to update or not. If updating to 10.7.3 download and run the combo installer.
Method #2 worked for me. I'm now back operational. Very bad experience. Lots of wasted time.