Here on the West Coast home values are going through the roof. Specifically in Silicon Valley shopping mall venues are looking at multiple use w/ high density housing/apartments in 2nd and higher stories and specialty high end stores and restaurants on 1st floor (street access). If done upscale, they are quite nice makes for a 'village' feel in the smaller cities/towns.
Therefore, it would depend on the REITs, their property locations, types of properties, zoning. I think they might rather sell individual parcels to someone/company w/ expertise to acquire special zoning (ie PUD) and building expertise. Once converted the cash flows and values would be huge (maybe 10x).
I would say at most 5% of properties in a REIT portfolio might fit this best use model and that is probably a high number.
If I was a developer, I would be scanning all the Mall REITs for possible multi density conversions and try to buy those parcels on the cheap. It's a lot of work (and money/time) to get a re-zoning approved. Parking has always been the issue on the ones I have researched.
EKS