Actually it's very easy to seal spoked rims and make them permanent. My BMW has been tubeless for 10 years and my 950 Adventure has been tubeless for 6 years and 47,000 miles.
Here's the technique very quickly but look on ADV Rider for more detail.
1. Clean the rim with alcohol.
2. Put it in a stand that holds it vertical.
3. Buy "GOOP" sealant. I've tried everything and it's the best so far.
4. Squeeze GOOP into the back of the spoke and cover 4 spokes.
5. Let set 5-10 minutes.
6. Do next 4 and repeat.
7. Let dry overnight and repeat again.
8. Repeat so all spokes get three coats.
9. Mount the tire and look for leaks with soapy water.
10. Repair any leaks (from the inside!) and you're good to go.
Sorry for the Hijack but if you like spokes (and who doesn't?) then you should know it's easy to make them tubeless.
Resume adoration of the cool concept bikes...
Gregor