I use the thing, I know how it works!

Are you saying you'd turn your nose up to a release of Poser that had Unreal Engine in the viewport?
If you did I'm pretty sure you'd be in a less than 1% minority.

It's one thing seeing this stuff done in the Unreal Editor, but it would be quite another to actually have it functioning directly in the Poser viewport.  You really need to check out the stuff they add to it on a constant basis, I get all this stuff in realtime in my Unreal Editor viewport (even on my old GTX460 cards).  It all depends on what method you use and what the materials themselves have been set up to do (the materials themselves are physically based and don't need baking).  I get the feeling some of you think this is a pre-baking trick.  It isn't, but if you want to bake for some extra quality, then you can, and all it takes is a single button click - no messing around with maps or multiple programs.

If I were faced with the choice of two figure programs, one that has Ureal Engine and one that doesn't, I'd go for the one with Unreal Engine over those GPU raytracers anyday, and I'm guessing everyone else would too.  GPU raytracers are nice, but they're not as fun and productive to work with as having Unreal Engine in a viewport, nothing can beat realtime interactivity and visualisation.  Whoever does this first is going to attract customers like they never did before.  Proof of that, will come when either DAZ or SM pull their finger out.  And due to me preferring the Poser interface, I personally hope it will be SM who do this first.

Unreal Engine in the Poser viewport would be incredible beyond words!