If its 64 bit windows 7 the answer is also no unless you are running 64 bit applications ....of which there are exceptionally few
Not quite true. You might want to run two or more 32-bit applications, each using 3GB, at the same time. Most likely scenario would be if you are running Virtual Machines. In that case the 8GB available to 64-bit Windows would be a distinct improvement over 4GB.