(I've also made a post about this on the official battle.net forums, but I'd like a fast response.)
Me and my guild have been having a crazy discussion about this topic lately. Since the first raid is approaching soon, I really need some clarification on this.
Our guild has been debating about the fact that wether it would or would not be possible to start raiding on Heroic difficulty from the start. The opinions have been different. Some people say it would be way too hard with the current itemlevel of heroic dungeons (so 630+-) and some say it would be possible.
Ofcourse with Blizzard's new changes in the pre-patch, flex -> normal, normal -> heroic & heroic -> mythic, it's been unsure what to do with the new content.
We've had several guild members who used to clear full heroic runs on previous content, just in case to give you guys some sort of image about our guild. We raid 5 hours a week.
So I was wondering what the forums have to tell us about this topic.
Kind regards!