Philips recently announced the CDO-H ceramic MH lamps, which are direct retrofit for mercury lamps without the need of external igniters.
Since this is the same as HPI-BUS in this manner, is the new CDO-H have a neon-argon penning mixture like the HPI series of quartz MH lamps?

I doubt it since the HPI lamps need more than 600v to strike and I tired with a normal fluorescent starter won't go. So to make the lamp self starting if it uses a glow bottle it has to be Penning mixture and with probe starting mechanisms it has to be Argon like mercury gas filling. The Neon in LPS lamps still need external ignitor which is more than 600v striking voltage. It's my opinions anyways...

I doubt it uses the starting probe - it was troublesome even with quartz (need compromises affecting arctube temperature management), with ceramic I would see it as nearly impossible.
I would rather guess for a combination of some sort of Penning mixture together with some pulser (glowbottle, heater+bimetal,...) and a starting aid (starting "antenna", auxiliary UV discharge tube,...)

But it's unlikely people will convert to CDO unless they can price it the same or less than a standard MV they replace. It either comes with the fixture more than a conversion. IMO the product won't sell well.

It would depend on the cost.
Definitely the only main advantage of MV - the reliability - would be likely gone, so installations using MV's for this reason would have to be rebuild anyway (e.g. placing two fixtures instead of one MV to reach similar reliability figures, complex and frequent relamping schemes,...) and then I would guess the "classic" HPS or CMH would win, mainly because of the predictable reliability record (the use of HV ignitor mean greatly lower sensitivity to exact lamp parameters, so it allow greater shift over time)...

Well in Singapore being a 'rich' country, I haven't seen a single CDO installation instead we opt for spiral CFL conversion for amenity lighting. Is CDO really that expensive?

I don't know the CDO, but I would say ceramic MH are of reasonable prices - they are not "super-cheap" (like incandescemts or MV's), nor expensive (induction, LED), so they are affordable for users, yet still attractive product for manufacturers...