You do not have to define the type twice. You can use var to define a new variable It figures out what its type will be. Not that difficult, since in vs2005, when you typed new it had 'guessed' it would be a StringBuilder (see example)
// example// in vs2005
int i = 123;
StringBuilder sb = newStringBuilder(1024);
// in vs 2008
var i = 123;
var sb = newStringBuilder(1024);