
cocos2d for iPhone v0.8.2-rc1 is available for download:
v0.8.2-rc1 highlights:
- TMX maps: HUGE performance boost when loading big maps
- Several improvements regarding actions: Jump, Bezier, Rotate, and compound actions
- Particles: uses world coordinates when using Free movement
Please, read the Release Notes for further information about the new features:


Should I be able to simply overwrite the current v0.8 beta library with this version?
are you using v0.8-beta or v0.8.2-beta ?
In any case, please read the release notes (RN)
The RN explains the API changes as well as the added/removed files.
http://www.cocos2d-iphone.org/wiki/doku.php/release_notes:0_8_2_rc1