It is immensely frustrating trying to get any info out of any of the big carriers. Vodafone have 0 information on their website, the Windows Phone page links to the iPhone page (awesome). They announced they were selling the Omnia W in October, it didn't arrive in November or December and it is now meant to be mid Jan. The story I heard for this was it was all Samsung's fault - Vodafone CSRs now say they have no idea of availability. Vodafone did sell the Trophy originally I believe.
Telecom is supposedly getting the Nokia Lumia 710s and 800s, but again no announcement, no info on their website.
From what I have been reading Mango has been doing well in Europe and is just starting to hit in any really big way stateside with carriers getting the Lumia 710, HTC Radar etc. and with Microsoft/Nokia doing a massive marketing push (probably starting at CES on the 10th).
For Voda and Telecom - I guess they don't see a lot of point. Windows Phone is a tiny piece of the market compared to Android and iPhone. They all seem to be going for the mid range handsets (710 and the Omnia W) as I suspect the high end handsets (HTC Titan) are an even smaller piece of the pie.
End result - if and when Voda launch the Omnia W I am expecting their price to be ridiculous (even with discounts) so will probably end up getting one parallel imported.