I have color class and star ratings sometimes working across PM 4.6, LR 2.3, and BR CS4. However, I have not been able to do the same with tags.
XP sp3 system
Here are the xml entries for an image that should have a tag:
<rdf:Description rdf:about=""
xmlns:xap="
http://ns.adobe.com/xap/1.0/">
<xap:ModifyDate>2009-02-20T10:55:02.56-06:00</xap:ModifyDate>
<xap:CreateDate>2009-02-20T10:55:02.56-06:00</xap:CreateDate>
<xap:MetadataDate>2009-03-08T16:28:58.289+05:00</xap:MetadataDate>
<xap:Rating>0</xap:Rating>
</rdf:Description>
Notice this one has class (label) and star
<rdf:Description rdf:about=""
xmlns:xap="
http://ns.adobe.com/xap/1.0/">
<xap:ModifyDate>2009-02-20T10:55:07.96-06:00</xap:ModifyDate>
<xap:CreateDate>2009-02-20T10:55:07.96-06:00</xap:CreateDate>
<xap:MetadataDate>2009-03-08T16:51:00.842+05:00</xap:MetadataDate>
<xap:Rating>3</xap:Rating>
<xap:Label>Good to Use</xap:Label>
</rdf:Description>
Also, xml files for .cr2 are not ending with CR/LF. The file only has LF (0A) and the terminating character.
That is a real bummer.
Finally, it appears that PM is modifying my .cr2 files if a xml file has not already been created.
This is totally unacceptable. (I opened a .cr2 file in PM, changed the tag, label, and rating and closed PM; no xml file was created; however, the modified date of the file was changed.) In this situation, the label and rating do not show up in LR. I've looked in the .cr2 file embedded xml information and did not find Rating or Label.
If this is correct, maybe I should stop testing the demo until some updates are issued.