A proposed update for UTR #45 has been posted. This update corrects the syntax of U-source identifiers to match ISO/IEC 10646 data files. It also introduces a new syntax with "UCI" labels to identify U-sources for unified ideographs which have been "orphaned" of their original sources.
Note that the review period for the proposed update has been compressed, so that the updated U-source listing and syntax will be available for use in the 10646 3rd Edition. Review feedback should be posted in time for consideration at the UTC meeting scheduled for August 1 - 5, 2011.
To supply feedback on this issue, see http://www.unicode.org/review/#feedback