My intellisense is running like normal, except that it doesn't show me the parameters of a function or any overloads.
If I type in
HttpWebRequest req = new HttpWebRequest(
I don't get to see anything about the constructor of HttpWebRequest. It's very annoying. This just happened in the last few days (I think) after I updated the Productivity Power Tools (again, I think).
I've tried playing with the options in Tools -> Options -> Text Editor All Languages and C#, and Auto list members is checked, and so is Parameter information.
In .NET 4 the HttpWebRequest constructor is protected and marked as obsolete. That means you can only call the constructor from a derived class. If you complete the statement manually it should give a "inaccessible due to its protection level" compiler error.