Vodafone has listed the Lumia 610 as "coming soon" in their Mobile Solutions Device Lists for May 2012. As well as listing the Windows Phone alongside the Lumia 800 and HTC Radar, a full-page advert is also included just before the Windows Phone section of the documentation.
Preaching all the features of the platform and the Nokia low-end device, the slide also contains a QR Code that links to the Microsoft ExpertZone. If you're not down for waiting until Vodafone releases the Lumia 610, Clove UK has the device listed at £180 unlocked.
In the meantime, check out our unboxing and hands on with the Lumia 610.
Thanks SilentAssassin for the heads up!