This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
You certainly won't be able to use a Java ObjectInputStream and have it deserialize some .Net output. If you used XML there might be a possibility. But I would say the idea seems pretty unlikely to me.