I can't connect to the ironlev website for some reason, but found a
video on another site where the prototype is tested. It mentions that it uses permanent magnets, so Haenk is right to say "massive" magnets.
I wonder what they are using as a power supply, because on the test track there is no overhead electricity available.
It is an interesting idea though, but keeping 20+ tonnes on the track at high speeds with just magnets might be a stretch. Testing on a straight track won't be enough to prove the concept.
Edit: found another video but it is in Italian. It does show the setup, with rollers to keep it in the track. That will give some friction and the length of one support might be a bit much for when the track turns. Don't know the smallest radius existing tracks have.