Product Version = NetBeans IDE 7.4 Beta (Build 201307092200)
Operating System = Windows 7 version 6.1 running on amd64
Java; VM; Vendor = 1.7.0_25
Runtime = Java HotSpot(TM) 64-Bit Server VM 23.25-b01

Given a new Netbeans Java project.
Class with following contents:
"
package testapp;

public class TestClass
{
    private Integer intVar;

    protected void testFunction()
    {
        Integer intVar;
        try
        {
            intVar = Integer.valueOf( 1 );
        }
        catch ( final Exception ex )
        {
            intVar = null;
        }
        finally
        {
        }
        this.intVar = intVar;
    }
}
"

Marking lines enclosed in >>...<<
"
package testapp;

public class TestClass
{
    private Integer intVar;

    protected void testFunction()
    {
>>        Integer intVar;
        try
        {
            intVar = Integer.valueOf( 1 );
        }
        catch ( final Exception ex )
        {
            intVar = null;
        }
        finally
        {
        } <<
        this.intVar = intVar;
    }
}
"
and executing "Introduce Method" (Alt+Shift+M) gives the following result:
"
package testapp;

public class TestClass
{
    private Integer intVar;

    protected void testFunction()
    {
        Integer intVar = introducedMethod( intVar );
        this.intVar = intVar;
    }

    private Integer introducedMethod( Integer intVar )
    {
        Integer intVar;
        try
        {
            intVar = Integer.valueOf( 1 );
        }
        catch ( final Exception ex )
        {
            intVar = null;
        }
        finally
        {
        }
        return intVar;
    }
}
"
which is not compilable. The parameter Integer intVar should not have been generated.