MMO Champion's got the tip on the Oceanic first kill of Illidan by a guild called Not Steamboat on Aman'thul. I'd actually call Archimonde the last boss in the game right now, although for the current Burning Crusade storyline, Bou is right-- Illidan is it, at least until the Sunwell.
But the kill brings up another interesting point with regards to Oceanic players. While they're often grouped with the US servers (unlike the EU or Asian servers, Oceanic and US servers are in the same place and subject to the same maintenance), are Oceanic servers that different that we should acknowledge a kill like this? This isn't like in China, where Burning Crusade just released. These Oceanic players have had access to Illidan just as long as an EU guild like Nihilum has. Why should we care if they kill Illidan? Sure, it's an accomplishment (just like every boss kill is, no matter how small or big), but is there even such a thing as "Oceanic first"?
Sanctus emailed Boubouille to argue just that and say that Oceanic servers should be considered separate, in terms of progression, from US and EU servers. He says that Oceanic players have to deal with the aforementioned maintenance schedule problems, as well as huge lag. So what do you think? If this issue of Oceanic progression as compared to the rest of the world hadn't come up, I wouldn't have mentioned this Illidan kill at all-- in my opinion, there is no such thing as "Oceanic first," because Oceanic players play on, more or less, the same realms that US players do. So should Oceanic realms be considered separately when comparing guild progression? Or should they be held to the same schedule and timeline for "first kills" as the rest of us?