People have asked me what exactly .NET offeres, what are it's advantages. If I could answer this in full I would be writing a book believe me but the truth is that I only got the compiler last week and have been reading about .NET for about 9 days. Don't blame me if there is some misinformation because it is my style to put stuff in my own words.
Common Language Runtime (CLR)
The programs that you compile in VS.NET are not the same, that is, the executable files themselves are different. They are now portable executables composed of assemblies and manifests (special identities). They are designed to be managed by the common language runtime (an execution environment). The common language runtime manages memory (garbage collecter), performs security (code verification), ensures robustness (just in time compiling), remoting, etc. Hence the term 'managed code'.
The .NET Class Library
A comprehesive object oriented library of reusable classes which targets all types of applications (projects) including web services, console, etc. In the past where you would open a file in C++ one way but in C you would use different code to open a file, and in yet another language opening a file would involve more different commands. Well the .NET Class Library allows all languages to open a file the same way. They all can use methods from the same library. So this is definately different.
But this is nothing, this is not a dent in the changes that you will find in transitioning to .NET. Ofcourse the new IDE is awesome. You have never seen such a rich IDE. This is nothing! .NET is a new methodology. I am trying to put it together but it will take a long time. Could use some help.