UML is a bit like SQL – useful as a lowest common denominator but you shouldn't expect much more of it. Just like SQL standards, UML has its uses, but it shouldn't be treated as a be-all and end-all standard to adhere to. There are still lots of methodologies. However, the big difference today is that methodologies are all extensible: they simply represent a starting point from which you can develop your own approach. So, UML did its job of getting rid of the rigid methodologies of the past, it is no longer necessary to do so for today's more flexible approaches.
