Immutable classes (models in MVC) simplify complex development in a number of situations (concurrency, testing, functional code flow).

You describe CQRS and Event Sourcing in your post http://abdullin.com/journal/2010/3/23/dddd-cqrs-and-other-enterprise-development-buzz-words.html
and left problem, could you give some technical solutions and examples, may be only on a couple of problems

Result{T} and Result{TValue,TError} monads extend the idea of Maybe{T} monad and allow to have strongly-typed and efficient failure handling, which does not have the drawbacks of conventional exceptions.

Composite UI application is an application created from loosely coupled components and UI blocks (components, too).

Even handling and dispatching is one of the tricky parts of such an application. Let's cover the scenario, when the application is really simple and does not need complex framework for that

Legacy code usually faces two fundamental problems: it needs to be rewritten and it is already bringing business value to the company.

In such situations project managers and developers have to find a balance between rewriting the entire codebase from scratch and painfully evolving existing application.

Distributed version control systems (like Git or Mercurial) get more and more popularity these days.

Although, there are some learning and adoption barriers, this popularity is well-deserved.

There was an article about some theoretical aspects of implementing monitoring and maintenance systems for the distributed apps. It definitely misses implementation details for the .NET environment.

http://abdullin.com/journal/2009/5/18/maintenance-and-monitoring-infrastructure-for-the-enterprise.html

Every software project starts with a certain set of rules constraining development. These development constraints (established willingly or by an external force) prohibit from using certain technologies, development approaches or tools.

Although, this might sound like a limiting concept, constraints aim to simplify the management of the project and increase probability of it successful delivery.