I just got a JIRA notice that Michael fixed Railo so that arrays and structs implement java.util.List and java.util.Map respectively. This is great news, because it means it's now possible to pass nested arrays and structs to Java APIs without having to manually rewrap them. From the ticket, it looks like the fix will be available in the next 3.0 beta, though I don't know when that's due out.
On the compatibility front, this means that the three major Java-based CFML runtimes (ColdFusion, Railo, and Open BlueDragon) all have compatible arrays and structs, which is a good thing if you need to write portable code that leverages underlying Java APIs.
[...] good signs that the community is serious about interoperability: Barney Boisvert reports that Railo has implemented the same underlying mechanisms for arrays and structs as Adobe ColdFusion and Open [...]