I wonder what the backwards compatibility to existing grafana and graphite implementations will be.
We have a tool/wizard that imports your dashboards from elasticsearch (removing that dependency for graphite users).
Keep in mind that grafana 2.0 will of course continue to work with graphite, influxdb and opentsdb for metric storage.
InfluxDB is not really suitable as a general purpose data source (storing dashboards as influxdb metric series was more a temporary solution so influxdb users did not need to install elasticsearch, and influxdb dashboard storage did not support tag filtering).
With Grafana 2.0 needs to store a lot more, users, accounts, user starred dashboards & preferences. So a more general purpose database was needed.