These are our school´s shodan requirements (were Aikikai/I.A.F. affiliated):
5 different defenses against:
5 different forms of Koshinage
5 different forms of Ushiro Hanmi Handachi
Tachitori (optional too)
Henkawaza (the examiner calls the technique)
Freestyle against 4 ukes.
That´s it, it usually takes about 15 minutes.