If you think about the all-time great NBA players, with an emphasis on the last 30-35 years (Jordan, Bird, Magic, LeBron, Kobe, etc.), most were guards and wings or players who, even if they were at power forward, were often on the perimeter, handling the ball, playmaking, initiating the offense, etc. People forget how dominant Shaq was in the 2000-2002 Lakers title run (averaging close to 30 points and 15 rebounds per game in some of the Finals MVP performances). People forget how reliably great Tim Duncan was/is.
Because perimeter players handle the ball so much, they are often put up there in the "best ever" debate. With post players, they are often considered the "most dominant" of an era or a particular time, but not necessarily the "best ever." Part of the reason why is that for all the scoring and rebounding, they still need a player to feed them the ball.
Having said all that, Taurasi is flat-out unreal. She is the player you *loathe* when she plays against you and that you *love* when she is on your team.
What separates Taurasi from other players? A few things come to mind:
1) Uncanny basketball IQ, her savant skill. She sees the game three plays before it develops. It is completely unparalleled in the women's game. Her ability to get the ball to players through her court vision is breathtaking to watch.
2) The hunger to win, to the point where she hates losing more than she loves winning. This is a very "Serena Williams-like" quality. Serena's greatest skill is her ability to play her best when she is in danger of losing, along with the best pure technique in the game and incredible speed and athleticism. Taurasi can be setting up teammates and appearing to be more casual, then drop 20 points before the opposing team has had a chance to finish sipping the Gatorade at halftime. And if you look at certain games (the 32 points "I just wanted to hit something orange" game against TN, the 2003 game against TN with the halftime shot and the late three, the 2003 and 2004 Final Fours, the 2006 WNBA game where she scored 47, the 2007 WNBA Finals, etc.), this is readily apparent. And like Serena, she has been dubbed "fiery" (on the complimentary side), "temperamental" (in the middle), and "brash" (on the less complimentary side). But it is that fire that makes Serena who she is and what makes Diana the player she is.
3) An uncanny belief in herself coupled with the ability to make those around her better. Alana Beard, as much as I love her, was not a vocal leader at Duke. She was a leader by example. And while she could rack up assists, she was best playmaking for herself and one other person, using screen-and-rolls or pick-and-pops. Taurasi can be a playmaker for herself and all others at all times. More importantly, she knows this, her teammates know this, and the opposition knows this.
Now, what does this mean for Stewart? She has a unique skillset. At this point in her career, I see a lot of Lauren Jackson in her (with some Penny Taylor thrown in), which means a lot of championships and MVP awards in her future. And it would not shock me to see her emerge as one of the best players ever. She could certainly be the most dominant player. But to get to the "best ever" label, I think she will need to display some more of the savant-like skills that Taurasi has (she may have them, she is still a very young basketball player) and be able to carry a team when it has great players (like Phoenix in 2007) and when it has merely solid players and young players, but no other stars or superstars (like UConn in 2003).
But I really look forward to seeing her develop. Again, it is hard to believe how young she is when you consider what she has accomplished at UConn and with USA Basketball. She really is a joy to watch, even if she is killing my team.