I think it's fair say that the Javascript API has a bright future with many starting to question the long-term life of plug-in's (Flash & Silverlight). It would seem to make sense for Esri to put more time and resources behind the Javascript API. That said, I think it makes sense to ehane the Javascript API with support for the Django framework which is based on Python. Most Esri web developers have strong experience in Python due to it's usefulness with Geoprocessing, so this would be natural extention of that.