The Making of Star Wars, Episide III - Revenge of the Sith features an interesting list of deleted scenes that will not appear in the 'Revenge of the Sith' movie. Here's the list courtesy of DarthyMarkyMark (contains spoilers - highlight to read):
6, 7, 8-14, 25, 30, 32, 37-41: FedCruiser scenes cut (Grievous killing Shaak Ti, the Jedi using their lightsabers to escape GG, underwater swim, climb through shaft, many of R2's hangar gags, many Palpatine cliffhangers)
48: Mace greets Palpatine and the Jedi right after the crash-landing
56: Yoda, Obi-Wan and Mace discuss the Dark Side in Yoda's quarters
60: Bail and fellow Senators speak about the Senate
68-69: Obi-Wan tells Padme of his worries about Anakin and that he nows they're in love
71: Meeting with Organa, Mon Mothma and Padme
73: Anakin informs Palpatine that Obi-Wan soon will have Grievous' head
74: Jar Jar greets Anakin at Senate
75: Anakin confronts Padme
76-77: Republic cruiser arrives at Utapau
83: Obi-Wan chooses his lizard, Boga
86: Mace talks to Yoda on Kashyyyk, telling him of his plans to arrest Palpatine
88-89: Padme presents to Palpatine the Senators' petition