People really do believe what they want to...
Kimi never hinted as a potential F1 return, and actually sounded quite the opposite in his press declarations so far. Last week end in Jordania he enjoyed a very decent result, coming P8 after having been constantly between the 6th to 10th fastest on every specials, which is a great improvement!
I suggest you take a look at the Pirrelli blog from Kimi:part onepart twopart three
One hint at Kimi's level of interst in F1:
Kimi Raikkonen wrote:"There’s still a long way to go as we have the final day left, and that’s sure to be another big challenge with some tough stages and hot weather. But I’m used to warm temperatures in Formula One, so that’s not a problem. Somebody actually pointed out to me earlier that it was the Malaysian Grand Prix this weekend; I hadn’t even realised until it was mentioned."
Given how straightforward he is, I'd personnaly believe it's no lies or joke but the raw truth. The guy is just enjoying himself a lot in what he describes as a very comfortable world.
Kimi Raikkonen wrote:"I have to say that I really like the world of rallying so far. It’s impossible to compare it to Formula One as it would be like comparing a square to a triangle, but everything seems just a bit more relaxed and friendly. Everyone has been very welcoming, but there’s still room for me to be myself."
see also: First WRC points for Raikkonen
I personaly don't believe anyone's going to see him again in F1 soon. And I don't regret it at all, I prefer a flamboyant and regenerated Kimi in a top level car in WRC than a shadow of him in F1...