[plt-scheme] Object serialization/persistence?

Has anybody implemented object serialization for objects of the 
v299/300's class.ss library or is about to do so?

I'm about to implement my own, non-general read/write methods for some 
objects of an interface externalizable-object<%>,which might be 
unnecssary work if someone was at the meantime working on some general 
way to write objects to a file port and read them (but using 
customizable or safe evaluation if it is needed at all). Perhaps in a 
generic format like sxml or xml? Is something like this in the work or 
planned?

Best regards,

Erich