As noted two weeks ago, the latest JDO 2.0 draft (JSR 243) was not approved. Also, as noted back in October, a lot of the JDO effort is now being channeled into JSR 220 (EJB 3.0).
Now Richard Monson-Haefel (J2EE: A Standard In Jeopardy?) posts The Death Knell: The JCP EC Rejects JDO 2.0, where he speculates that the rejection will "make JDO a footnote in the annals of Object-Relational persistence." He believes all significant Java O/R persistence effort will now occur in EJB, not JDO.
Interestingly, Richard asserts: "Right now it makes more sense to use JDO or Hibernate than it does to use EJB 2.0/2.1 container-managed persistence" (for new development) because EJB 3.0 will likely be more like the former than the latter. I've said otherwise, that WebSphere customers should stick with J2EE. The way I've heard it, the J2EE vendors have a very strong steak in supporting their customers by making sure the new versions of EJB and J2EE are backwards-compatible with code developed for the current ones. Yes, prominent JDO and Hibernate figures are on the JSR 220 committee now, but so are EJB 2.x people who care very much about getting current customers to buy the next version of their products.
I don't decide these things for IBM, but it's hopefully a no-brainer that current customers will be supported going forward. Therefore, I would stick with J2EE, and change when J2EE does, not before.