A few thing that Eli and I have already begun hashing out:
Modular loading of Pollen functionality
Re-write of isObjLiteral (Eli is the man with this one - he wrote an excellent implementation of isObjectLiteral() prior to joining PollenJS)
SQL style querying of JSON objects
Also wanted to note that Eli developed and released JSandbox, which is also a Worker-specific library and was released about 2 months prior to Pollen. Unfortunately we were completely unaware of this, otherwise we would’ve brought him on sooner!