Hi Prasad, I am having a similar issue. C# intellisense does work for me in Blend (Blend 3 RC) but not for everything. For example if I have a named component, intellisense will not pick up on it through Blend, only in Visual Studio. Another example is the following line:
myGrid.Visibility = Visibility.Visible;
the myGrid does not pick up ( although it is defined in the Xaml)
the .Visibility does
the second Visibility does not
and the .Visible is not an option under the list that appears after typing the ".", but I am able to use this property and it works correctly.
Thanks and I hope I was able to help add some detail to this issue