The UDS 12.04 event is taking place at The Caribe Royal in Orlando, as announced by Jorge Castro in this email announcement. The Linaro event again will be co-hosted during the Ubuntu Developer Summit. There's uds.ubuntu.com, but not many other details beyond that at this time.
With the last event, UDS Budapest for Ubuntu 11.04, it happened to unfortunately take place partially during LinuxTag, which was going on back over in Berlin. There is no direct collision this time around with any major Linux events, but it does fall directly after the Linux Kernel Summit and LinuxCon Europe that's taking place in Praha. At least the Ubuntu location is ideal for surfing to burn off the beer from Oktoberfest and LinuxCon Czech beer.