Roger is already "semi-retired". He is just "going through the motions". He clearly is NOT working hard to stay in shape, or keep his game sharp (note the decline in his consistency, and his "spare tire").
I disagree with that, he says he still works very hard, and considering what I saw in Roland-Garros, which I clearly was surprised of, I think he does.
After all, most of his defeats were to Djokovic and Nadal who do have a great year, well Djokovic a great year, Nadal a very good one.
Roger is just now hoping for the "dream draw" where the likely winners (Djokovic, Nadal) are upset, or injured (real injury, not one of Rafa's "injuries"). I am sure Federer is already resigned to picking up, at most 1 last lucky Slam.
That would be sensible to think that, but I don't think players and especially Fed makes so many calculations : it's not the way they do, the hope and confidence in themselves pulls them, and Fed is especially hopeful and confident, that has been shown very often in his carreer.
When Roger stops making the QFs of slams, he will officially retire in less than a year.
People have been used about Fed "always making finals", "always making semis", now "always making quarters", I don't know how long this will last but it's a huge anomaly in the history of tennis.
There's no reason that in the future he cannot make a final or semi once in a while, while he loses early or R16, quarters other times.
What's important is not what he "consistently does", but what he hopes he can do, if he thinks he can still win a slam even if he loses early than semi more often, there's no problem at all, Sampras was like that.
Now yes, it's important for that that he still feels competitive against the younger players, and also that he keeps a seed correct enough.
Especially I don't care whether he's number 3 or number 4 behind Murray, but what I'm mostly concerned about is if he loses number 4 to Ferrer or Söderling or Del Potro. So far I think the risk is not huge yet.
Anyway I think being in seeds 5 to 8 will still be correct enough for him to hope a slam win, but being further could really make him lose too often before final rounds.
But now we're only talking about what will make think
Fed of retiring, but between the moment when you think about it and the moment when you actually take the final decision, which is a very painful one for someone who's loved so much tennis, there's still much time.
You see Hewitt ? Haas ? Gonzalez ? Ljubicic ? even Safin, who was not the greatest "tennis lover" at all, how long did he look "semi-retired" in his mind before actually retiring ?
Of course he will lose more and more and his regular goals (which is different from winning once in a while) will be less and less ambitious, but that's the normal life does go.