No, all it may do is change the DBA skill set a little. If your data wasn't important enough for a DBA then you wouldn't have had a DBA anyways and SimpleDB does nothing to change that.
Conversely, if your data matters enough to you then there will be a DBA somewhere who knows the data well enough to ensure it survives.
Who are you going to call when your application corrupts your data? Amazon probably won't lose your data on purpose but they can't prevent mistakes.
However, this could be an opportunity for an startup - outsourced SimpleDB data administration.
> There's one significant cost that SimpleDB users can avoid: keeping a database administrator on the payroll.
cringe cringe cringe.