Digital Terrestrial has
3 common flavours of DVB-T, though if your set does MHEG5, MHP, DVB-T2, AAC, MPEG4, VHF and UHF, it will work in most DVB areas.
There are then 4 incompatible non-DVB DTT standards.
Will it have Component for USA, SCART for Europe, Analogue RF (several kinds of SECAM, PAL, NTSC etc) for countries not using DTT yet, or with Analogue Cable?
People used to buying "grey" imports will import the North American version and find it works almost nowhere else in the world on Digital.
Even HD is country specific resolutions and frame rates, even on HDMI. Or will Apple pretend 25i and 50p don't exist. Will it support 24p and 48p for better North American disc playback of stuff transferred from Cinema?
Or will it be like the original iPhone, almost only a GUI and packaging exercise with standard electronics?
If they do release a "real" TV, any one buying it is wasting money, as it will be more expensive and more restrictive than a similar quality non-Apple TV.