"We will at least have a week or two of not hearing "WoW is so Easy, or maybe we are just so Leet"

You'd think so, but as noted elsewhere in these comments, there are always going to be people who assume that, because an elite band of professional gamers downed Yogg in 24 hours, everybody will have cleared the Hard Modes within a week.

"Why do everything in the first 24 hours."

In their case, it's obvious. World/Continent/Realm Firsts mean more press coverage and more prestige for the guild, which in turn means better sponsorships and more tournament invites. It'd be like if your job required you to work all night on a big project; you may or may not enjoy it, but you do it because that's why they pay you. Ideally, the boss recognizes your extra effort and gives you a bonus or some vacation time.

As for the rest of us, those who aren't professional gamers, I see no reason to burn through the content. Spend a few weeks, get your people geared up. Go back to Naxx25 and EoE25 to patch any gaps in your gear. Learn the Ulduar fights the hard way rather than reading and executing somebody else's strategy.