You fail to recognize the significance. First off...I never said McCain was right-wing, but he indicated that he would appoint far-right justices. Perhaps he said this to cater to the right-wing, but I have to believe that he meant it.
Second - it doesnt matter that Obama replaced a liberals on the court with moderates. Had Obama NOT been President, the likelihood is that McCain would have appointed justice much more far to the right, if not completely right-wing. Obama being President prevented this.
Third - Obama was smart, like GWB in appointing fairly young justices, which ensures their "lifetime appointment" will carry through for much of the rest of my life.
There is also a strong likelihood that Obama may even get another appointment within the next two years, further cementing the inability of the right-wing to overthrow the court.
The Court is not right-leaning at this time. It is very moderate, which despite my hard-left political leanings, is where the court should be. The whole point of the Supreme Court is that they not have a political agenda one way or the other. While personally, I would love justices who share my liberal beliefs, I understand that it is better for the Court and the Country that they don't.
The best chance that the right-wing had of getting a right-wing activist court was lost when Obama was elected. That is why I thank GOD every day for President Obama.