Impressive, but I'm sure someone out there has done faster, but never recorded it. Even so, 5:39 is impressive. Blows my 7:42 run out of the water, it does.
I doubt it. Achieving this time takes massive playing skill and knowledge of all the shortcuts and tricks. Things that have been found at speed demos archive. Jiano is a contributor to the thread and so he knew all these things which made him achieve the time 5:39.
A new run is in production by TP_Fox, though he hasn't gotten very far yet. Even if he doesn't beat Jiano's time, it will be placed in a different category - not obsolete the Wii run. There are many things on the Wii that the GC doesn't make up for speed, such as faster loading times and the ability to instantly aim where you want. GC does however have the advantage of backflipping off the horse and more steady aim. It isn't impossible to beat time on the GC version, as many small timesavers have been found since Jiano's run was submitted.
Watched it when I got the link from the other thread. And yes, it's insane.
Now they should do a speedrun to get all of the stuff in the game.
Actually a 100% run is in planning by Mr_Potter over at SDA. Don't expect it to come out very soon though.