I think a mix is happening. Rondo is really freaking good, and getting better every year. His decision making is his biggest improvement this year. But he is also benefiting from all the attention given to the big 3. Those guys demand a lot of attention.
As good as Rondo is, he is still a 3rd tier all star. (That's not a bad place to be.)
Here is a rough breakdown of the tiers:
1st tier - the superstars: Lebron, Wade, Dwight, and Kobe
2nd tier - The hands down perennial all stars (unless injured): D Willimas, C Paul, Nash, Durant, Carmelo, Gasol, Bosh, Dirk and maybe Stoudemire and Brandon Roy.
3rd tier - Rondo, Joe Johnson, Ginobili, Rose, Tony Parker, Gerald Wallace, Pierce, Garnett, Al Horford, Duncan, Boozer, etc.