Would be nice if Visual Studio would inspect the javascript and css files in the project and show intellisense for the files in partials, user control, master pages, pages, etc.

Bake inversion of control into the framework and reduce the reliance on inheritance. This will allow greater extensibility and enable new scenarios. A good example of this is MVCTurbine (http://turbineproject.com) - rather than developers having to roll infrastructure themselves, they could hit the ground running with their IoC container of choice.

Spark is great but doesn't have a very good developer story inside VS. Having intellisense work on Spark views would be really great, not only code-wise but also for HTML and JS

OpenID, ADFS, and other redirection-based login protocols don't fit the membership provider interface at all. Please add an interface that can be implemented by an OpenID library decently.

The asp.net providers (membership, profiles, roles, etc) are a bit dated. This does not only include the specific implementation of the providerrs (SQL providers) but also the base classes themselves.

Just like you have many refactoring tools for c#, it would be nice to have many of those features for JavaScript

Currently when I publish my site/app it stay's online. It would be better to drop an app_offline.htm during publishing so that my app doesn't behave in a funky fashion.

Ability to support multiple sites from single code base see Rob Aston video for example http://bit.ly/multi-tenancy and more info http://bit.ly/multi-tenancy-1

T4 is no longer just a tool used internally by VS, but is being increasingly used by developers for code generation. It would be great to have syntax highlighting, intellisense etc. out of the box.

I appreciate this is probably more of a Visual Studio feature request than an ASP.NET one, but as T4 is used a lot within ASP.NET projects, particularly MVC ones, I figure it's worth a mention.

ASP.NET dynamically adds JS files to pages. These files should be combined and minified into 1 file before being served on the page.

Store all of my settings associated with my LiveID or OpenID, and let me easily pick between for example my desktop, laptop, presenter, etc. settings. If I walk up to a friend's machine, I should be able to grab my settings from the cloud and when I'm done, he can revert to his, with minimal effort.

After some time certain parts of code i n a project end up not being used anymore and just waste screen estate. It would be handy if Visual Studio could detect this and warn you about it.

I would love to use Script# similar to how Google Web Toolkit works. Your Javascript story is still pretty weak in terms of allowing us to easily make complicated AJAX applications.

Someone already submitted refactoring for JavaScript, but I would like to also see complete JavaScript Code Navigation as well. Anyone who has worked with several/large JS files in VS would kill for rightclick->Go To Definition.

CSS is so much easier to maintain with the .less
It allows you to make variables in css files.
It would be great with intellisense etc for this great project
http://www.dotlesscss.com/

Add please more MONO support/compatibility

As per David Fowler's prototype, support for binding to other other control properties and properties on data objects using a WPF-like syntax (declarative) or from code-behind (imperative).

I can't stand the idea of having to install Visual Studio on a build server. MSTest should be standalone like NUnit (or any other test frameworks).