Mr. Peter McKinnon from Rotacaster, http://www.rotacaster.com.au sent some photographs of the prototypes today of the insert bushes with the Lego cross axle bore.
They look fabulous & appear to be of no comparison with any other omni-wheels available for the Lego Technics/Mindstorms system.
Peter has run a limited amount due to unit cost initially, but once we get some feedback on them we will move forward with tooling for them.
Peter is due back in Australia on the 29 July 2010, and by that time should have samples of new 48mm production wheels which should have improved roller fitted. He will also have some samples with a much softer durometer roller for us to assess prior to considering whether to add tread to the wheels.
Images of the new Softer Rubber Rollers which will give more grip should be available in a few days.