I thought MOS had altivec support, to be honest. Stuff is only faster if its written specifically for Altivec.
Edit: OK, well heres basically what I said. I can't post as much as I'd like (NDA..), so heres some of whats already in the public domain:
* Almost entirely PPC native. Only exceptions are console.device (which is already being converted to C), a few CLI commands like BindDrivers, and ARexx.
* Native graphics
* Native AHI and MUI as contribution
* Working NallePUH for paula audio emulation (and, I have started work on adding CIA timer emulation to get things like AHX working, but I won't make any promises that it will actually get done).
* Native TCP/IP stack
* Excellent SDK with easily installed optional modules for things like SDL
* Enhanced Workbench, with all the features of OS3.9 plus a lot more
* JIT integration is basically done
* Native Warp3D is in the hands of the beta testers and a few developers, with Radeon support
* Native drivers for Silicon Image ATA and Serial ATA drives