Based on what we know from the massive ending sequences that all run simultaneously, Ternian has come up with this informed speculation on the sequence:

Spoilers!
* Obi-Wan, Anakin and Padme are fighting the arena creatures.

* Mace arrives with about 200 Jedi while back up forces are on their way.

* A fight erupts between the Jedi and Droidekas, Battle Droids and Super Battle Droids.

* Mace and Jango begin to fight.

* Ki-Adi-Mundi and Plo Koon make way to the Trade Federation Ships that have appeared out of huge silos in the ground. They board the Control Ship.

* They attempt to shutdown the main ship but fail.

* The Jedi lose huge numbers of knights in the arena and the small band left are cornered.

* Suddenly thousands of Clone Attack Gunships descended and begin to blast the Confederate Forces.

* In the area outside the arena, the Trade Federation Ships are parked on the terrain surrounded by Confederate Forces. THOUSANDS of Republic Military Cruisers begin to unload Clone troopers

* Yoda appears in the doorway of an Attack Gunship and saves the last band of Jedi and Padme in the arena.

* Clones begin to fire upon the Trade Federation ships parked outside.

* Droidfighters are released as Jedi Starfighters begin to engage in the battle.

* The Gunship that saved the cornered Jedi attacks a Trade Federation ship but is hit by fire.

* At the same time, a Geonosian speeder is seen making it's way through the battle below and is spotted by Obi-Wan. However, Padme is knocked out by the blast from the TF ship.

* Padme is saved by Clones below and begins to lead them in the battle.

* The Gunship is parked next to a tower while Ani and Obi-Wan go after Dooku.

You can also read up on more opinions and new information on the climactic sequences including Attack Craft and more in this JC thread. Here's a second summary from COJ:

1, Obi-Wan, Anakin and Padme battle Arena creatures.

2, Mace and approx. 200 Jedi show up.

3, Mace battles Jango, in background Jedi battle droids, Geonosians, SBDs and Droidekas.

4, About 15 Jedi are left in the middle of the Arena - last stand.

5, Gunships show up and whisk the Jedi away.

6, Gunship carrying Obi-Wan, Padme and Anakin flies over battlefield outside the Arena, it is the Geonosian Landing Field. This is where the large battle takes place not the Arena.

7, Gunship spots Dooku and gives chase.

8, Padme falls out and is recued by Clones.

9, Obi-Wan and Anakin continue (after small argument) to challenge Dooku in his hangar.

Great stuff - be sure to add you comments and reaction to the forum thread as well!