Hope you're not sick of seeing Robert Downey Jr. as Tony Stark in Marvel's increasingly massive movie universe, because he's not going away anytime soon. This isn't all that surprising considering this was never truly in doubt, but during his press tour for Iron Man 3 he let it be widely known that his contract with Marvel was up and he had yet to sign a new one. Everyone saw that for exactly what it was, though; a very public way of saying, "Hey, Marvel, want me to do more of these? It's going to cost you."
As for what that cost is, we have no idea, and frankly we don't care. When you're the inseparable star of a franchise you launched and your latest film earns $1.2 billion at the box office, you've earned the right to use some PR to increase your power at the studio (watch him do just that in the below clip from The Daily Show). So don't worry about what Marvel paid to get its original Iron Man back, just be glad he is back. However, he may not be back in the way you want him.
Marvel broke the news itself and its post about it confirms that Downey Jr.'s new deal is only for The Avengers 2 and 3. In case we need to make that even clearer, that means an Iron Man 4 is not currently on the table. If you ask us, that's a wise move. IM3 was a great cap on that trilogy and it stands alone as a cool, different kind of superhero movie thanks to Shane Black. There's no need to try to go back to that solo well again. Let some other Marvel characters get their time in the spotlight.
So, that means we won't be seeing Tony Stark put on that badass suit of his until The Avengers 2 hits on May 1, 2015. Of course, he could pop up for a cameo in another movie before then, but do you really think Marvel would ruin that kind of a surprise this early on?