Only four channels on the DTT service are in HD, those being:
TVOne 720p TV2 720p TV3 1080i DemoHD 720p
On TV1/2 currently all material is SD upscaled to 720p, TV3 is 1080i for some programming normally indicated in the EPG, all else is upscaled SD material. All other channels on the DTT service are SD(576i). All channels on the DTT service are encoded using mpeg4.
All channels on the DTH (satellite service) are SD(576i) and encoded with mpeg2.
I suspect it will be a long time before any more channels are provided in HD as the ones currently in HD have a shortage of source material as it is.