Now, when the definiton is made, I am afraid most probably (as far as I can say it now) I will not participate in the regional ones as the matters are not much interesting to me (f.e. I do not understand one single word in finish and I am not much interested, excuse me, on how taxes apply in Malta, nor the specific problems on the translationpair zulu to tagalo.)
Yes, regional conferences are targeted at ProZ.com members who live in a specific country or region and the specific issues they are dealing with in their careers as freelance translators and I understand that tax issues in Malta are not relevant to someone living in Germany. However, similar sessions at a regional conference in Germany might be of interest to that same person. Also, these specific sessions will be complemented by more generic sessions, some of which may even be held in English, opening up possibilities for attendees from further afield.
Regional conferences are not meant to limit the range of attendees. On the contrary, they're meant to be opportunities for those who for whatever reason do not want to have to or cannot travel too far from their home/office or would not attend conferences where all sessions are held in English.
If people look at what's on offer at any given regional conference and also take into consideration the attraction of the location, they may find it is worth attending after all. At the end of the day that's an individual and subjective decision.
AND -very specially- much less "international flair among participants" will be found at them. This was for me a very, very important criteria to participate in a conference, in both either regional or international. Now this criteria may exclusively apply to international conferences, unfortunately...
Following my comments above, I don't think that the international flair will lost...I would not be at all surprised if regional conferences continued to be attended by ProZ.com members from every corner of the world.