If you're waiting on the artifacts from the Maven central repo, you may be waiting a while. From the Spring side, we've published our artifacts to an internal repository that the Maven team syncs against. For some reason, the Maven team hasn't synced it yet (and hasn't for a couple of weeks it appears). We don't really have any control over this, but we've emailed the Maven team to get it sorted.
If you are desperate for 2.5.2 artifacts, I whole heartedly recommend the suggestion earlier to use the Amazon S3 release repo. As you can see from this blog post, we already repositories like this for milestones and snapshots. The post doesn't mention a release repository, but it follows the same pattern as the other two.
If there is no reply from the maven team by this afternoon (GMT), I'll be blogging to recommend this particular course of action.