In 5.2.1, if a profile had a blank hostname, it would prompt you for the hostname when opened. In 5.2.2, it seems that profiles with blank hostnames do not work at all (the only available option is to 'Edit' the profile, add a hostname, and save it).
We often SCP into a ton of different machines, which fit into a few different presets (key / port combinations). It is impractical to create a preset for every one of these hosts, so the feature to type it in each time (without saving to the profile) is massively helpful.