There are multiple interfaces to HIVE and Hive-Engine. I imagine that Hive.blog was intended to be the prototype of a HIVE based web site. HIVE encourages groups like PeakD, Waivio, ecency and all of the tribes to create alternative interfaces.
I imagine that they will do the same with Hive-Engine.com. I suspect that they want Hive-Engine to be a basic prototype with LeoDex.io and tribaldex.com being the souped up interfaces for the exchange.
With this idea in mind, I would expect the changes to be added functionality and not so much of a GUI update.