Spring 3.0.1 explicit supports the second release candidate of hibernate 3.5 aka 3.5-CR-2. Migration is very easy with maven:
old pom.xml (part) for hibernate 2.3 and jpa 1.0
cglib cglib-nodep 2.1_3 org.hibernate hibernate-annotations 3.2.0.ga org.hibernate hibernate 3.2.6.ga javax.persistence persistence-api 1.0
new pom.xml (part) for hibernate 3.5 and jpa 2.0
org.hibernate hibernate-entitymanager 3.5.0-CR-2 org.hibernate.java-persistence jpa-api 2.0-cr-1