Mordeth wrote in about his latest yearly update to the Mordeth TC Site. Seems like that disease World of Warcraft has afflicted quite a few people lately, but he's recently gotten over it.
Portals is where it's all at nowadays in Mordeth-land. Can't imagine doing stuff without those now. Levels look more life-like with added details and perspective on floors and ceilings. In many cases it's actual easier to use a portal instead of old-fashioned detailing. For example, creating a ceiling with some details (beams, skylights, perhaps a moving ceiling fan) over a floorplan with eg. lots of crates used to be a pain... now, you can just leave the ceiling bare and slap on a ceiling portal to add the details much more easily, using much less sectors and in much less time.
That's only one of the paragraphs, so you might want to check out the rest.