Conference finals? My guess is that it would take a kind of reverse Murphy's Law - everything that can go right does go right.
Let me give an example:
Stoudemire reaches elite status as a PF on both the offensive and defensive end. I find it improbable that this will happen this year, but it is not out of the question.
Johnson plays consistently at a high level. He's shown signs that he is capable of being a solid, even star player but not consistently enough.
Marion returns to the level of play that got him to the All Star team and loses his aversion to contact. This is not unreasonable, but hardly a sure thing.
Richardson becomes a more consistent shooter, defender, and passer than he was with the Clippers. He has a lot of talent but played too much like Clipper to be outstanding. With luck he could emerge as an elite player, but it is not a sure thing.
Nash becomes an adequate defender. Supposedly Nash at least tried to play defense on the Mavs but the results weren't there. He will have to step it up if the Suns are going to get out of the first round.
Barbosa becomes a real point guard and reduces his tendency to foul too much. Barbosa showed some signs of making progress as a PG, but he is still very new to the position. Come playoffs, he will have to be solid as a point guard and control his fouls so he can stay in the game.
Lampe becomes an adequate rebounder and defender. Lampe has the potential and showed a little progreass this summer, but he will have to make a lot of progress if the Suns are going to be a serious contender. He will also need to be more of a passer and less focused on shooting every time he gets the ball.
Hunter becomes a consistent NBA center. He's had his moments but they were relative few. If he can block shots, rebound and play defense, it might be enough to make the Suns a contender. If he can't, the Suns will struggle.
Jacobsen becomes a consistent scorer to go with high percentage shooting. Casey averaged only 6.0 ppg in 23.4 minutes, which is inadequate. He won't get those kind of minutes this season, but his outside shooting could be very helpful if he can score consistently.
Voskhul learns to play smarter at center. Jake makes too many dumb fouls and gets caught out of position too often. If he played smarter he would be one of the better backup centers in the NBA.
Vroman lives up to expectations in playing defense and rebounding. Vroman lasted to the second round for a reason, but he has the energy to play the role Bo Outlaw used to play.
Even if everything went right, it will be no easy task. The Spurs and Timerwolves have strong, deep, veteran teams and in the playoffs experience really does matter. But if everything went right, the Suns would right up there - but I'm not holding my breath.