They would've scrapped it even before Release if they didn't see any future on that.
Fact is: you're a bunch of MW haters and just want an AH because it's more convenient, but players have played for about 9 months and they've got used to the Market Wards. The Market Wards is Here, and you can't possibly change that fact because people use it everyday.
And no, people will not leave the game because of the Market Wards. Hell, even within Aion where after some days that AH was a... FFFFFFFFFFFFFFFFFFFFFFFFFFFF***********************CKING MESS! Things overpriced, some rare sh*t put for few kinah and sh*t like that, but I didn't leave the game because of that.

But with the thinking that the Market Wards will remain in the game, you can still think of an "Auction House" in a place like Ishgard where you can sort every retainer's stuff in every city's Market Wards and buy it from there.
And if they combine this with the functionality of the Market Wards discussed in this thread then you'll have Convenience + Comfort. Bi-winning.