Help me pick a phone!!!

I am trying to decide which phone to switch to next. I've had 3 iPhones (3, 3GS and 4) since 2008. As great as it is, I am now bored with it. It's clear on Wednesday 12th no new form factor will be released, the iOS will look the same. I want a change.

Samsung Galaxy S3

or

Nokia Lumia 920

I realise the latter has not been released or properly reviewed yet, but based on the initial reviews and what we know of WP8 - what should I go for?!

I realise this is very subjective, but I'm bored and i've run out of beer. Humour me?