两个词组的意思完全不同，与时态无关。as it is有两种意思：

  1.=in fact  事实上，实际情况是  例：我们原本希望今天能做完它，但实际情况是我们或许要等到明天才能做完它。
                                  We had hoped to finish it today, but as it is we…(后面是“或许要等到明天才能做完)
  2.已经，早就是  例：不要再说了，你现在已经够麻烦的啦。
                            …；you are in trouble as it is.

  as it were只有一个意思：=in other words
                                    we may say...
  例：他可以说是个当代的福尔摩斯。 He is, as it were, a modern XXXX.

                                                                               to be continued...