The field of software engineering management has become a monocultural. It's agile, agile, and nothing but agile. Even though agile is performing very well, it's definitely not the pinnacle of engineering management and there must be superior approaches how to deliver better software even faster. Furthermore, whenever it seems that there's no alternative to the status quo something is always brewing under the surface waiting to erupt when the conditions become ripe. Even though I'm very vigilant myself about any disturbances in the agile force, it is very hard to see any alternative today to agile approaches. The only remotely possible alternative to agile that I see today is open source organization. Most of the people relate open source with software such as linux, firefox, or apache server. But what impresses me about open source more than the software delivered, is the organization behind open source projects. Traditional engineering requires elaborate organization put in place first, before it is capable of delivering complex artifacts, such as bridges, highways, nuclear reactors, or accounting software. Open source manages to deliver complex software without building the organization first instead relying on self organization of people around a common goal. I'm pretty sure such approach is a total blasphemy to MBA trained managers of today, but there already exists very successful companies such as GitHub and Automattic which are organized in such a way. It may very well be that these organizations are vanguards of future trends and that the organizations of tomorrow won't be employing workers anymore, but will be accepting committers instead.
If you're interested in how GitHub is organized, check the talk by Zach Holman. It's a bit young and naive, but there would be no revolutions in this world if it wouldn't be for young and naive people!