ok. animation format v2:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>animations</key>
<dict>
<key>dance_1</key>
<dict>
<key>delay per unit</key>
<real>0.2</real>
<key>restore original frame</key>
<true/>
<key>frames</key>
<array>
<dict>
<key>spriteframe</key>
<string>grossini_dance_01.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_02.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_03.png</string>
<key>delay units</key>
<real>0.5</real>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_04.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_05.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_06.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_07.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_08.png</string>
<key>delay units</key>
<integer>2</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_09.png</string>
<key>delay units</key>
<real>0.5</real>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_10.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_11.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_12.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_13.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
<dict>
<key>spriteframe</key>
<string>grossini_dance_14.png</string>
<key>delay units</key>
<integer>1</integer>
<key>offset</key>
<string>{10,10}</string>
</dict>
</array>
</dict>
</dict>
<key>properties</key>
<dict>
<key>spritesheets</key>
<array>
<string>animations/grossini.plist</string>
<string>animations/grossini_blue.plist</string>
<string>animations/grossini_family.plist</string>
</array>
<key>format</key>
<integer>2</integer>
</dict>
</dict>
</plist>
gles20 branch has a working version. It is still has some bugs. I will fix them tomorrow.
https://github.com/cocos2d/cocos2d-iphone/commit/908fb72701b7034b1ef26dbe356b994a74d5096c
UPDATE: updated format