Relation vs. References vs. Entity Reference for managing node-reference-type relationships References
Entity Reference
Relation


It seems like there are several active modules that all have similar functionality. Can anyone offer any information as to which branch appears to be the most promising / likely to survive &amp; thrive? Any advice is welcome.
As of March 2012, the References module project page is now recommending Entity Reference as a replacement.

For basic node-type references, Entity Reference is certainly easier to set up than Relation.  I think a good general rule would be 


  If you can do what you want with Entity Reference, use that.  Otherwise, go with Relation.