I had the same problem this morning. I was out of town with the car (1000km weekend, my total km is 1087 lol) and didnt notice any problems. I fueled up with 91 octane in Ottawa (petro can) and drove home, no start problems at all.
This morning i started, and as said above, the start sounded "weak" the rpms were low, the oil temp as well, as it usually goes right up to 90. Putting it in reverse did nothing. Went park, then reverse again and no probs. After filling at Shell, same deal so when i had to do some driving for work i made sure that i held the key during the initial start (not just forward until i hear the starter kick in) and it worked fine. I probably held the key up there for a second or two.
Either way, its concerning, but i can get around it. If it keeps up after i get the shit petro canada gas out of my engine i'll call my dealer.