Bug 11863 Update Test Suite action does not allow to remove
What the action actually does is RECREATE the test suite based on the selection in the dialog. I do an update on a test suite which contains X. It is no clear that if I only select Y in the dialog that I'll end up with X being removed. Normally "Update" shows the content of the existing stuff (dir, zip) and allows to modify this. I think renaming the action (and the dialog) to Recreate Test Suite would solve the problem.
org.eclipse.jdt.junit/src/org/eclipse/jdt/junit/wizards/NewTestCaseCreationWizardPage.java
public IType getClassToTest() {
		return fClassToTest;
	}
	/**
	 * Sets the class to test name.
	 * @param canBeModified Selects if the super class can be changed by the user
	 */		
	public void setClassToTest(String name) {
		fClassToTestText.setText(name);
	}	
	/*
	 * @see TypePage#evalMethods
	 */
	protected void createTypeMembers(IType type, IImportsStructure imports, IProgressMonitor monitor) throws CoreException {
		fIndexOfFirstTestMethod= 0;
		createConstructor(type);
		if (fMethodStubsButtons.isSelected(0)) 
			createMain(type);
		
		if (fMethodStubsButtons.isSelected(2)) {
			createSetUp(type, imports);
		}
		
		if (fMethodStubsButtons.isSelected(3)) {
			createTearDown(type, imports);
		}
		
		if (isNextPageValid()) {
			createTestMethodStubs(type);
		}