Terms listed alphabetically, not in creation order

criticality: 
Critical
Drupal7: 
Open

When entering terms from admin/content/taxonomy, they're saved in alphabetical order (i.e. no weights) rather than the order they were entered.

So when inputting:
One
Two
Three

You get

One
Three
Two

shown in the term listing or node/add drop down.

Implications: 

Taxonomy sorts by name and weight.

Solution: 
Ensure the last entered term has the highest weight in the vocabulary when submitting terms. Users can still set terms back to alphabetical if they want to.