.NET framework: new features

A few weeks ago I changed the target .NET framework for my application to the 4th version. Recently my Resharper told me that my variable "MetaDescription" hides property string System.Web.UI.Page.MetaDescription

After small investigation the piece of code that worked earlier:

    HtmlMeta MetaDescription = new HtmlMeta();
    MetaDescription.Attributes.Add("name", "description");
    MetaDescription.Attributes.Add("content", ((IFriendlySEO)Page).DescriptionString);
    Header.Controls.Add(MetaDescription);

was开发者_运维问答 replaced with much more readable:

    MetaDescription = ((IFriendlySEO)Page).DescriptionString;

(same for MetaKeywords).

Question: is there any useful source that can give a list of such new features?

Question 2: is there any book (I mean printed version) of such items (I've seen "Essential C# 4.0", but it is for .NET newcomers only. Is there anything that could be fruitful for those who want to became a Guru?)

Thanks.

I think MSDN's What's New in ASP.NET 4 and Visual Web Developer page may be what you're looking for.