I dont rate steve nash as highly as everyone else because hes only effective on one side of the court. Steve Nash has no D. While Arenas has only played 15 games in his last 2 years, it cant be argued that Rondo is better than Arenas right now. Nor can the arguement be made that Rondo is better than Kidd RIGHT NOW. Rondo is nice, but one playoff series doesnt propel you above players that are flat out better.
Steve Nash has as much impact on his team's success, even with his defensive limitations, as any other point guard in the league.
Gilbert Arenas is more of a shooting guard, and until he is back and consistently playing at a high level (took a big step in that direction last night), I can't put him in the top five anything. He hasn't played in two years.
Jason Kidd probably isn't top ten anymore. If I had to choose one player, for just one season, salaries are no consideration, team composition is no consideration, I'm taking Rondo, straight up, over Kidd. He had some really great years, but they are all way behind him now. Unlike another aging point guard, Nash, he can't shoot, so his impact on the game is severely diminished as he gets older and slower.
Rondo had a significant impact on the Celtics season last year, and especially with Garnett missing a lot of time, he really stepped it up. That really showed in the playoffs, but it was there all season. Like I said, I'm not a huge Rondo fan, but I am a believer. He's not what I'd want in a prototypical point guard, but he does a great job for his team, and he's an on-the-bubble star in this league. He's right outside the top five, at least, and it's likely that he gets top five money from someone.