I like this idea very much. I'm so glad you're suggesting this - it's certainly a need that (as far as I'm aware) has gone unmet for far too long.
I have a suggestion, and I do hope that I'm not "beaten up" by anyone for saying this (ohhh....I should just learn to shut my mouth, grin), but I believe that it would be even MORE beneficial to maybe set up individual chat/blogs for the different professions. I know that it would be a social group, rather than a therapy group, but my own experiences as both a facilitator and participant in such groups is that when the demographics of the participants in one group are too varied, they tend to break up into smaller groups with more similarities anyway. Some participants then feel even more isolated because they don't feel they're receiving the support they went their to get.
I don't know the logistics of starting this kind of chat/blog either, so anything is better than nothing. Just offering my thoughts in the beginning stages of development in case it's feasible to do it that way.
Whoa! Hold up! I've just thought of a suggestion for your chat/blog. Yahoo Groups! There are other free options out there that I'm now recalling, but I believe that Yahoo Groups is probably the easiest, quickest, and least involved option to start the group you're speaking of. You can set a group description page that explains to visitors what your group is about, any group rules, etc., you may want, and that also has a link for interested people to request to join.
I'd be more than happy to help you out with this if you need it.