At present domain auctions primarily operate in a two dimensional market of Keyword and Extension. The market gets its value from, and is a reflection of, the web itself and the 'Search' values of the keyword and extension.
However, the web is not static. Today "Location" and "Real Time" is being hard-wired into the info-architecture of the web. So domain value is no longer just about keyword and extension, place and time are rapidly becoming major players in the value matrix of search and therefore domains.
Location + Time = Depth (in space, from the point of observation). So in a very real sense, the domain name value matrix is also experiencing a 3D revolution. Though most domainers will not see this as their mind set has been conditioned to see a 2D market, including for domain auctions.
Keyword and Extension are 'domain' elements whereas Location and Time are 'NameSpace' elements. Together they form a Domain Name ecosystem, of NameSpaces, in cyberspace. But, as mentioned, auctions to date are virtually all about the name, and not about the space.
IMO, NameSpace auctions are inevitable... and a natural evolution to "Domain Auctions". I'm NOT saying domain auctions will be replaced, or go 'extinct'. But there are only so many category killer .coms --and its about time "the industry" started selling the neighborhood and not just the killer homes.
So I think a 3D Auction is in the not too distant future. Clearly, judging from all the regs just here at NamePros, the 3D NameSpace is a very vibrant ecosystem. Ironically, for all the 5-niner (99.999%) 3D=Fail posters, a sign of a vibrant NameSpace ready for auction is one with a lot of regs.