According to this article:

AN INSIDER AT Sun Microsystems says there's frantic discussion inside the company about big problems with the Java platform that, he claimed, "prevent general acceptance of Java for production software within Sun".
He said: "It strikes me as hypocritical for Sun to blame Microsoft for any failure of the Java platform when Sun's own engineers find developing common software applications in Java impractical".

FUD?

Well, no. Read the original memo, straight from SUNW itself, here.