Among the devices listed as coming soon at O2 UK is the O2 XDA Zest.
This mobile phone will give you great access to functionality with a large screen, Wi-Fi, AGPS, and 3G. You also get a 5 Megapixel camera with 4GB built-in memory with expandable memory as well as quad band reach.
Other than that, all we know so far is that it will be manufactured by ASUS and will be powered by Windows Mobile.
Pricing has not been revealed but we should not have to wait too long for it as it is expected sometime in November.
If RIM phones are more your thing, the same O2 UK Coming Soon page also lists the BlackBerry Pearl Flip 8220.