I know that both the MorphOS community and the AmigaOS4 community haven't expressed interest in a PS3 port (primarily because the PS3's hypervisor prevents access to 3D hardware), but what if IBM were to change its policy of limiting access to Cell processors and allowed outside developers to work with the chip?
At 3.2 GHz with its additional 8 SPE processors the Cell could make a powerful core for a multimedia computer. One of its few limitations (besides its in-order execution) is the limited amount of XDR ram it can address. However, considering that the Efika runs fairly well with less memory a tight, compact OS (like MorphOS) would be well suited to it.
The main reason I brought this up is I've inquired directly with IBM, and they may not be as adverse to the idea of outside development as was once thought (but don't get your hopes up just yet).