does Visual Studio 2010 not have a "join lines" keyboard shortcut?
EDIT - That is when on line X anywhere, I hit a shortcut key once, and then line X+1 joins to line X (eliminating CR between them so to speak)
As I far as I know it does not.
However, you can create and save a new VS macro using the following code:
Sub JoinLines()
DTE.ActiveDocument.Selection.EndOfLine()
DTE.ExecuteCommand("Edit.Delete")
DTE.ActiveDocument.Selection.EndOfLine()
End Sub
and assign a keyboard shortcut to it (like CTRL + j)
This code will join the current line with the one right below it.