I reckon it's just reverse psychology and Hugo's just trying to rile the Ipod people into putting Vorbis in their next firmware update.
The other thing is that playing "sensible bitrate" vorbis (64-160kbits/s) is much, much less intensive on both CPU and memory than higher bitrates -- audiophile nutters can and do thump the Vorbis encoder until it generates 400kbits/s or even 500kbits/s files. If the Ipod Linux people are decoding 128kbits/s Vorbis at 80% real-time, 1CPU then they aren't on course to decode 256 or 320 in real-time on both CPUs. Likewise, I haven't looked at Tremor-lowmemory, but I'd be very impressed if it could decode 500kbits/s Vorbis inside the 96kbytes of internal SRAM.
Peter