It seem that's hibernate is a little bit intrusif. If I want to refer to a type safe enum in an object persisted by hibernate, i must hinerit my enumeration Clase from persistantEnum which is a Hibernate Interface.
Is it planed to solve this issue, by using reflexion for example (using conventional toInt and fromInt methods) ?

You can easily map a normal Typesafe Enumaration (thats a pattern, use Google) with a Hibernate UserType, non-intrusive.

Have a look at http://www.hibernate.org/172.html for workaround...