[arty-fishL]

Emmm... just as I described.
In depth description:
You need to have definite subparts as components or groups in sketchup. Also make sure all front faces are facing outwards, I just do this with a custom style I made. Then export as google earth file (.kmz). Then open it as a zip and extract the contents. There should be an untitled.dae file in there and a textures folder.
Then open blender, you need the collada 1.4 (dae) importer to import it and the ase exporter to export it. Import the dae file. Then export as ase. When exporting it select all the options (exept centre objects if you want to keep your axises).
Then open the ase file in notepad and remove all the periods in the names. They should be like "ID##." , with ## being a number, just replace the periods with underscores. This usually takes a while, so I am working on a python (actually a python, not Alice jython) script that should do it automatically. Ive made one that should work properly, problem is the ase files are too big so Im getting an out of memory error when running the script.
Next step is to import into Alice. If all goes well then the file should be there with subparts you created and other subparts (maybe blender creates them, dont know). All the textures should be perfect and the model should look as it did in sketchup. The subparts will be on one level with the ID12 etc names, just rename the subparts if you want to.
Then save it as an a2c file to your gallery and add an icon from a screenshot to it if you want.

This is quite a long proccess, but it gives good results, the space deck, homespace and tiles models are all mine and they all worked quite well.