Flickr geotagging has clearly taken off in a big way, with the FlickrBlog reporting that 1,234,384 photographs were geotagged in the first 24 hours of the service launching, with another 400,000 9 hours later. In general the service has been very well received and the ability to do more complex searches is a real bonus.
However, there's a fair amount of disappointment outside the US and Canada; the maps used for the service are poor at best, with very little detail, making the service close to unusable. I tried it myself and there are large tracts of nothing in the UK, and the map for London is not terribly good. However, the folks at Flickr are aware of this (as reported in the linked blog entry) and it's something they're working on, and are promising 'more, better, soon.' I (and a great many others) are looking forward to it.