Just in case you missed it, I wanted to highlight that the importers are now live. The October 21 update goes into detail on the different types of imports and the overall features of the import functionality. 

One of the features I'm most looking forward on the importers is they will automatically identify up to 50 rows and give you a chance to fix the errors. If you've ever done data imports before you know how important clean data is; however, stuff happens and sometimes incorrect info sneaks through even the most carefully scrubbed dataset. This feature should save some time while making it clear which row(s) contain the bad data.