Ordnance Survey have just released their May 2013 version of OS Locator, the comprehensive gazetteer for GB. According to my calculations there are 5247 new entries and 3694 removed entries since the last release in November.
I've updated my comparison tool Musical Chairs with the new data. New entries tend to show up prominently in the "recent relevant updates" view mode for a few days after an update, so this is a good way of taking a look at what's changed in your area.
I'd suggest GB mappers take a look at their area, even if not for the purpose of mapping - new releases of Locator often reveal some interesting things about new building projects and developments.