> since MorphOS doesn't support SMP, isn't that overkill?

It's not exactly like market is overflown by newly available Power Architecture laptops/notebooks/netbooks (let alone single-core ones) for users of a PPC-only OS to choose from, is it? ;-) And besides, this device is primarily targeted at Linux, which supports SMP.
If it comes to fruition, the MorphOS team can decide whether or not to support it. And if they do, they better make use of the SoC's ability to have unused cores/clusters (almost) completely switched off.