In the last 10-15 years, the Market Arcade has really come back to life. There was a student conservation study carried out in around 1989 (in UCD Richview library) that showed considerably more dereliction than today. Agreed, it's a bit shabby, but it is a living building complex that really adds vibrancy to this part of town, not least the mix of shops, stalls and cafes. I'd be worried that any major conservation project might push up rents on the units, forcing out the existing traders and altering fundamentally the character of the place. It changed hands a few years back and the new owner/s have done a good job of maintaining or introducing just the right mix, both inside and outside. In fact, I'm not sure whether the external units are separately owner or are part of the whole. Anyone know? Also, I'm intrigued by the basement- apparently it's huge, but I've never seen it (aside from the individual basements of some units- Road Records, a couple of the cafes, one of the hairdressers).
There's a picture of the interior of the arcade from the 1950s or so in the cafe at the George's St end (Simon's Place) showing cars parked inside, and the entrance to the Market Bar retains shopfronts in the 'lobby' area (unsure if they're original though). If it was to change, I'd love to see an English Market style daily food market, i.e. butchers, fishmongers etc., rather than a fancypants food emporium. It's something this city sorely needs. But I'd rather it stayed as it is for now, with maybe minimal running repairs, particularly as the DCC project for the old fruit and veg markets on the northside will hopefully provide such a food market as you see in Barcelona and elsewhere. Then hutton could have all the fresh fruit and veg he needs!
PS One criticism of the market- a few years ago they took out the old floor of what seemed like sandstone flagstones (doubtful, but my memory's hazy) and replaced it with the current tiled surface. Not only does it look too new, it's lethal when it rains.