That could be... it depends on how they try to define that gift/power. I know it was suggested that Sylar's ability wasn't a power, but I believe it's why he can cut open people's heads (by pointing his finger), which would make it a power. If that's the case, then Peter doesn't have that power either.
Sooo... if Adam's power was ever blocked (by say... the Haitian) the same thing would have happened? OR did something else happen like papa P used one power to age Adam while he stole his power at the same time?
If Sylar has Peter's power sponge ability, where did he get his understand everything power? I'm guessing he got it from his adoptive dad since we haven't seen him, but he could be a fluke who has two powers naturally. Do miss Sylar being a bastard, but Arthur is a decent villain.
I think what he meant was now that Arthur has absorbed all of Peter's power, he now has the ability to absorb other powers without touching, just like Peter.
If we're lucky, the writers have realized that Peter's collection of powers just fucks everything up, and they'll give him some totally different and managable power. Maybe from the formula or whatever.