Bug 134740 [Wizards] PDE product wizard is not obvious to use.
see attached image. The wizard for creating a new product opens with a file name initialized to ".product" which is selected. Generally this would imply that this is a good default but if you start typing you will replace the text with something else that is also a good name. If you require an extension for a file you should add it yourself like the "Export Archive" wizard.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/dialogs/WizardNewFileCreationPage.java
advancedButton.setFont(linkedResourceParent.getFont());
			advancedButton.setText(IDEWorkbenchMessages.showAdvanced);
			GridData data = setButtonLayoutData(advancedButton);
			data.horizontalAlignment = GridData.BEGINNING;
			advancedButton.setLayoutData(data);
			advancedButton.addSelectionListener(new SelectionAdapter() {
				public void widgetSelected(SelectionEvent e) {
					handleAdvancedButtonSelect();
				}
			});
		}
		linkedResourceGroup = new CreateLinkedResourceGroup(IResource.FILE,
				new Listener() {
					public void handleEvent(Event e) {
						setPageComplete(validatePage());
						firstLinkCheck = false;
					}
				}, new CreateLinkedResourceGroup.IStringValue() {
					public void setValue(String string) {
						resourceGroup.setResource(string);
					}
					public String getValue() {
						return resourceGroup.getResource();
					}
				});
	}
	/**
	 * (non-Javadoc) Method declared on IDialogPage.
	 */
	public void createControl(Composite parent) {