Is 10.5 months too early?

Erik and Liam are as different as night and day... and I ran across another example today...  Liam, at 5, is still hesitant on the potty, Erik on the other hand...

He's been sitting on the potty in his diaper for the past few days while I used the facilities - tonight he was wet anyway and I was going to change him after I had done what I needed to do, so I took off his diaper and he went and sat down and...

He pee-pee'd in the potty and was so excited:


I am going to encourage him, but I don' know how the logistics would work - has anyone else had success with early toilet training?

On another note, he woke up with the worst barking cough and congested chest, so we're off to the pedi to make sure it's not serious... or get some relief if it is...