Export as KMZ

KMZ files are commonly reffered to as 'Google Earth Files'.

Repeat the steps as for exporting as a DAE file, but this time choose 'Google Earth File (*.kmz)'.

Import the KMZ file in a new Photoshop document, and you shall find the form of the object, without its skin.
Save the file as a PSD and close it. Put it in a new folder, together with a copy of the DAE folder in which you found the skin as a JPG.
Open the PSD in Photoshop. No skin (see below).

[SketchUp 8 / Photoshop CS6]
In the 3D panel open the layer SketchUp, open its sub-layer instance_0, open its sub-layer Component_1 and select its sub-layer Material. See how the Properties panel changes.
In the Properties panel click at the bottom the left folder button, called Normal:. Choose 'Load structure' and select the JPG. There you are.
(After this, you cannot choose 'Load structure' again.)

[SketchUp Make 2015 / Photoshop CC]
In the 3D panel open the layer SketchUp, and select the sub-layer Material. See how the properties panel changes.
In the Properties panel, nearly at the bottom (you might have to strech the panel a bit), click the folder-button and choose 'Load structure' and select the skin in the DAE sub-folder. You might expect the structure to appear between the structures that are already present (see below), but that is not the case. You must now click the arrow next to Diffusion, and [2014] then choose the name of the structure JPEG, or [2015] choose Swap Structure and choose the skin from the DAE. There you are.
(After this, you cannot choose 'Load structure' again. Close and re-open the file for that.)

[2014] I exported the 3D layer from Photoshop as KMZ. I then imported that in SketchUp. Only a wireframe appeared.

The KMZ file is a zip file, just like f.e. an ePub or a Style Builder STYLE file.
Change the extension of it to .zip, and unzip it. Mac: search for mac + file + change + extension.
You now have a file called doc.kml and a folder called models.
In the folder you find a file called untitled.dae. You also find another folder there called untitled, containing the skin, called texture.jpg. These files of course can be used to import the file correctly in SketchUp.
In Photoshop you can work with this new DAE also of course, and note that the object is much brighter then the one obtained through the KMZ file.

If you click the doc.kml file, you shall see your object, placed on the earth somewhere in Colorado (Google!), in Google Earth. See below. Mind you, this is only a 2D; you cannot 'walk around' it.

In Photoshop 2015 this is different now. There is no KMZ export option anymore. Now you have a seperate menu item, 'Share 3D layer in Sketchfab'.
That was untill the november release. Its is like in 2014 now again.

For Sketchfab see https://sketchfab.com/. Go there and click 'See more cool features' for an introductory video.