Yes, in the xJson plugin settings you can enable this, although I'm not a huge fan of it myself. You can also edit dialogkaitoast.xml in your XBMC skin if you want more control over the popup. I think it is possible to disable the popup sound for example.
Or if you disable "true fullscreen" in XBMC then you can use the regular VC OSD popups, provided that it is all running on the same system. Unfortunately, depending on your setup, true fullscreen may be necessary in order to get smooth video playback.