What are the 10-man strict rankings, you ask? GuildOx ranks the progression of guilds all across the different realms. The strict 10-man rankings are, essentially, 10-man raid groups that never have access to the 25-man versions of the instance. This means that a strict 10-man raiding group will never have gear or drops obtained through 25-man raiding.
To be considered and ranked on the GuildOx strict 10-man rankings, members of the 10-man raiding group can never earn an ICC-25 or ToGC-25 kill. Even though ICC-25 drops the same iLevel gear as ICC-10 heroic, GuildOx discourages the practice, as this allows strict 10-man raiding groups to gear up twice as fast. "Strict" means "strict." In addition, strict 10-man guilds usually only have a limited roster of between 10 to 12 people, since most others go on to the 25-man versions of the encounters.
According to Sheeana, the toughest phase was the first, as the Lich King's minions on heroic scale in power exponentially. These are raiders using, at the most, iLevel 264 gear.
For the full interview and announcement, including the criteria for the strict 10-man rankings, visit GuildOx. You can learn more about the criteria surrounding the strict 10-man rules here. Again, big congratulations to Typhoon Struggle!