Lantus released Amiga360 - an port of the P-UAE v2.3.3 Amiga emulator for XDK-homebrew 360s:

Amiga360 P-UAE 2.3.3 for Xbox 360 Console

- Based off P-UAE V2.3.3
- Simple and easy to use GUI
- Full Mouse/Keyboard support
- OCS/ECS/AGA/Picasso96 emulation
- Hardfile emulation
- Savestate support
- BSD Socket Emulation (experimental)
- Filesystem emulation (experimental)
- Drive click support
- Prebuilt config files included.
- Tested and working with Amiga-SYS, ClassicWB and AIAB

This homebrew was built with XDK This makes the software you want to download 'illegal'. So find the download link yourself
Source- Dev Ramblings of a Drunken Coder