Function here argued that it should be 160 ALUs based on conjecture from the die shot, but I don't know if it was ever corroborated.
In the end it was.
SDK leak confirmed 32 ALUs (160 shaders), process was confirmed to be 45 nm NEC for the GPU / edram. Die area and number of register banks turned out to be good indicators.
None of this undoes the fact that Zelda U looks absolutely beautiful. At some point in 2016 I'm going to be plopping down money on console with a GPU I wouldn't have wanted in my PC ten years earlier. A feat only Nintendo could pull off.