I'm writing a specialized plugin host which currently supports VST2.4 plugins only. When I have a bit of time, I will also include support for AudioUnits on the Mac and LADSPA on Linux.
As one of the purposes of this host is to facilitate in plugin development, I was also considering VST3. However, a quick search at KVR's host database reveals that the only VST3-capable hosts are those made by Steinberg (though please correct me if I am wrong here). Though a handful of plugins support VST3, I haven't come across any plugins which only support this format and no others, while the reverse is certainly true for AudioUnits, RTAS, etc.
Is there any point to supporting VST3 in a host? Is this something that people actually use or want? Or is everybody happy just using VST2.4 until the end of time?