VS.NET comes in many editions with some limitations.
For example: VS.NET Express does not allow you to have any plugins (or used to, never checked anymore) which means you can't run your NUnit from there and expect code-coverage instantly show up once you ran them.
Their NuGet solution somehow seems limited compare to Maven eclipse plugin where it can download the JAR, JavaDoc, and Source if required whenever someone needs to navigate the source code of 3rd-party lib.
You shouldn't be using the Express version for professional development anyway, you really need to use the paid version - that's a whole different Java vs .NET debate running into OS vs proprietary that will never end.
As for NuGet, as soon as you build, all code, docs, etc are right there and it's up to the creator of the library to have created the info. It manages versioning and updating for you as well.
Unfortunately the whole debate of OSS vs Proprietary does matter when it comes to "which tools is better". I know it'll never end but it affects the playing fields.
The fact that you can get up to speed very very quickly without spending money or talking to Finance, MS Sales/re-sellers using Eclipse+plugins and Java+OSS libraries/frameworks that were more mature is probably a significant point on this debate.
The money thing is a semi-moot point at this stage due to BizSpark. Yeah, it's a bit "drug dealer"-esque with the whole "first hit's free" thing, but you can use the full MS stack/toolset for free for 2-3 years or until you've got 1 million in yearly revenue. At that point, you can easily afford the relatively minor premium MS extracts from companies using the platform.
For example: VS.NET Express does not allow you to have any plugins (or used to, never checked anymore) which means you can't run your NUnit from there and expect code-coverage instantly show up once you ran them.
Their NuGet solution somehow seems limited compare to Maven eclipse plugin where it can download the JAR, JavaDoc, and Source if required whenever someone needs to navigate the source code of 3rd-party lib.