One of my favorite unknowns, thanks for reminding me of its existence.
Anyway, Aphex has been releasing a lot recently including effectively his entire back-catalogue not that long ago so there is likely little new that he could bring to the event at the moment, especially considering the length of the slot. I wouldn't let that entirely discourage us, but don't be surprised if it is just something akin to the full original peel sessions (Xyz and Bad Day included) and a soundboard recording from a live set. That would be fantastic, actually, and a sign of activity from them and the potential for a new release.
On the flipside, they could address us all by username and claim that their new song is dedicated to us and all of our wonderful posts before performing it and mailing us a personal invitation to Hexwalker SunRanch in Calilerno for a studio tour in which a hench glasweigan fellow looking out of place in a suit (instead of a footy top) constantly tells you "no eye contact with the sandisons please, sir. Keep within the turquoise line at all times".
It wouldn't be me, though, I've said some nasty shit here