It's likely that we (in the UK at least) will start to see stocks of the Z8 in retail channels the week beginning 25th June, although due to warehouse / delivery times etc. this may slip to the week beginning 2nd July.

Vodafone will have a slight exclusive on the phone, as the initial shipments are going to them, but O2 and SIM free handsets should be available a week or so after the initial Voda shipments.

Up to date information can be found here: http://www.motosmartphones.com/z8/availability.htm

Vodafone now says July (http://shop.vodafone.co.uk/index.cfm?go=paymonthly.comingsoon&WT.svl=link1).
This phone slips more than Torvill and Dean ;-)

Now available in Spain, with others VERY soon - See Here (http://www.intomobile.com/2007/06/30/moto-z8-now-available-in-spain-rest-of-europe-and-asia-to-follow.html)

The Z8 is now available in the UK on Vodafone.

O2 and SIM free are due within the next two weeks (Vodafone have a short exclusive in the UK)