Whiteside have started manufacturing metric-sized spiral upcut carbide bits to suit domino sizes. They are only sold through Woodcraft stores in the US.
Details of the bits are as follows:
RU1805 2 flute ¼” shank 5mm cut diameter 5/8” cutting length 2 ½” overall length List price $21.00 WC # 148048

RU2006 2 flute ¼” shank 6mm cut diameter 7/8” cutting length 2 ½” overall length List price $21.00 WC # 148049

RU4858 2 flute 1/2” shank 8mm cut diameter 1” cutting length 3” overall length List price $54.00 WC # 148050

RU4910 2 flute 1/2” shank 10mm cut diameter 1 1/8” cutting length 3” overall length List price $54.00 WC # 148051

With these bits, router owners who have built one or other of the Rocker morticing jigs (see my blog below) can use dominoes for floating tenon joinery without needing to buy the Domino itself. I dare say, however, that eventually most, like me, will want to buy the Domino when finances permit.

By the way, it is not necessary to buy the 8 mm metric bit, since a 5/16" spiral bit works quite satisfactorily for 8 mm dominoes.

Rocker