At our dojo, all the kyu tests are basically scripted. The student knows in advance what basic movements and techniques are going to be required.
The only exception to this is the requirement of one (or two at the higher kyus) "previous techniques" -- anything from an earlier kyu. That's not really a problem for people, until you're an ikkyu and then sensei changes ALL the lists, down to 9th kyu. The 8 kyus worth of "previous techniques" become "additional new techniques" in many cases!
I think the above isn't too revolutionary, though.
On our last shodan test, the candidate only knew what weapons kata were going to be asked, and what attacks
uke would use.
After basic movements and weapons kata, the test consisted of sections based on the known attacks. This particular test had yokomenuchi, ushiro ryotemochi, and another that I don't remember...
Anyway, for each section, sensei simply called out techniques at random. The candidate had to perform them from right stance and left stance, then be uke for one.
After sensei was satisfied that he had called enough techniques, then he called for jiyuwaza based on that attack.
Repeat above for each type of attack.
At the end, the candidate had to give an oral talk on some budo- or aikido- related topic chosen by sensei.
(I always thought that was cruel -- this poor fellow can't even catch his breath, he's so exhausted. Quick! Make him give an oral report! Sheesh.)
For higher dan testing, I have (like Jun) seen multiple-uke jiyuwaza, and "teach-a-technique". The last, I think is a really great idea, and appropriate for higher-level yudansha testing.
Perhaps nothing really startling here, but what the heck. It's Friday, so I thought I'd post...