Excellent article!   One way I've found to measure my own progress as a DBA is to read job descriptions of Senior-level DBA positions and find out what they're requirements are.

I'm often suprised about certain areas I've never considered before.

Some job descriptions emphasize more of a development role, some more of an operations/administrator role --- so you have to kind of know what you're own goal is as well.   But it's a great place to start.