Jungle Dave might have great insights into scalability issues, but I don't see how creating Jungle Disk required any scalability knowledge at all. Amazon handled scale-out. JungleDisk is a nice abstraction layer over S3. Perhaps their server-side augmentation stuff (public web view of files, etc.) required some scale-out?
Isn't scalability supposed to be one of their core competencies?
They haven't been able to generate web logs for almost a year, maybe more now, eta is still several months off -- for log files.