Ensidia got the world-first kill of 10-man Algalon a bit over two weeks ago. They say the 25-man version is "not an easy fight," "highly gear dependent," and "a significant difficulty increase over the 10 man version." Apparently last week they got him to 4%, only 1% over the threshold to beat him (he gives up, like Mal'Ganis in Culling of Stratholme). That must be frustrating as heck.
Well, congratulations to Ensidia, once again! I wonder what they'll be doing until patch 3.2 comes out.