I do not have insider news on that.
StarHub named them (HD) is because they take the data directly from the MediaCorp EPG. If you go look at SingTel Mio TV's EPG they also take the same data.
And StarHub is always ready to broadcast HD (look at the amount of HD channels they have now), the only question is whether they want to carry it or not.
for starhub EPG, i noticed that they didn't put (HD) word at the titles for ch8, but hide it inside the description... but for suria and vas, they put (HD) at the titles... dunno why got such diff.
anyway, starhub EPG has removed all the (HD) word now, except for ch5 and HD5... seems like they don't want ppl to ask about the HD thing.
why ppl keep asking "when" pay tv will carry hd, that's because there is no timeline announced to the public on the discussion... so the public is interested to know the progress and an estimated waiting time, eg. next mth, mid 2014, end 2014 or after 2016.
and also last time when starhub finally carried HD5, there are some disagreements like this:
No HDTV for some because of StarHub-MediaCorp spat
as for whether starhub is going to open new channel numbers for mediacorp hd, or re-use ch 102-108, i'm still waiting... of course separate channel numbers will be better as hubstation hd users can choose to record sd (less space) or hd (more space).
but looking at mediacorp only got ch8(HD) and no ch8(SD) for DVB-T2 transmission, after 2020 when analogue and DVB-T shutdown, mediacorp will only maintain 7 HD channels and no more SD channels.
so i guess eventually (after 2020), only HD channels will remain.