What implementation problems has the industry claimed to have solved many times, but are still soaking up all of your time?
- Cross platform GUI - mobile devices have blown this issue wide open.
- OO to RDBMS mapping - how do I map this attribute to that field in that database using that framework. You get the idea.
- Interface definitions - ..., CORBA, COM, EJB, WSDL, ..., etc
Can you think of any others?