Gauging interest level as this would require a Mac to do the development.

Allow users to customize the naming convention for layers and materials with a custom name or with the SketchUp filename.

Will there be a Mac version ? And if yes when ?

The SU Plugin could prompt for a save location each time a model is exported. After export the .mtl would be automatically edited with the correct paths to the textures. End result being that materials would not need to be re-linked.

This would be a powerful feature in conjunction with advanced material options in SU (glossiness, glow, colour, no draw, glass shader, diffuse, specular, emissive colours etc)

Way to reuse one material on multiple assets and just assign sub material numbers within SU.

SketchUp Plugin that automatically divides the model in components, each one composed of max 64000 vertices, and each one named per material. to make easier the exportation to CE every time that you make some changes of the level on SU model.

Create support for Skyrim's - Creation Kit. I'm one of the Admins for "The Westeros Project" a free full-conversion modification for the Skyrim Creation Kit engine. (http://www.creationkit.com/) We have been using sketchup for much of the development & conceptual process but it would be helpful if we could also use it get objects from Sketchup into the engine with ease. You can some of our conceptual work here: http://www.moddb.com/mods/the-westeros-project/images

to work with detail bending at trees and blend-/dirtlayers in cryengine like this http://freesdk.crydev.net/display/SDKDOC3/Detail+Bending

I use the bug fixed Version 2.1 to made some simple Tests with sekcthup 2016 and unity. It doesnt´t metter what i do - i get always objects without any textures......

SketchUp already supports it on on 2016 version...

Before PlayUp, I taught myself how to properly produce UVs inside sketchUP using the sketchUV plugin, and it works very well. PlayUp solves nicely the scene exporting issue, but its mapping tool is rather limited. I wish I could turn it off, so it wouldn't mess my own UVs when I export. C'mon, guys, how hard can it be?

Do I need Sketchup pro to use playuptools? Or it can be used with make and use fbx exporter no problem?

I love to see an exporter for Quake3 stuff, gtkradiant.
ASE and MD3 files I think.

Reinforced bar schedules for concrete slabs,bridges, columns, beams

Might be a usefull tool, I mean the tutorial page is good but with a wiki you can add more information, even verified users can pitch in.