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I also believe CPW are taking pre orders too.
Edit. Just checked and they are, on a Vodafone account too so if you want it from Vodafone you may have to use that route.
Vodafone won't provide information to this in regards to what's going to be available.
If you decide to use an independent like Cpw then ensure if it's an upgrade then they properly upgrade you and not add a second line or out you on a business tariff. If you upgrade or take out a contract through them then you become their customer.
Also discounts such as VEA are only available if you take out a contract/ upgrade with Vodafone directly.
A person could as suggested buy the phone and then drop onto a sim only type contract.
Update for anyone interested:
Appears I can upgrade via the CPW website the process checks for your account details with Vodafone before ok'ing everything.
Is there any news on this yet?
I'm ready to upgrade and I'm looking for a Google Pixel. I don't want to go elsewhere but will if vodafone are not stocking this phone.