I have been interested in the same issue. So far the following (in no particular order) is what I have observed/read/written about so far:
-virtual group fitness classes;
– catering more to special population groups (trend toward more standardization, regulation, etc.) especially with the baby boomer crowd and now the obese since its formal declaration as a disease last week; and
– health care and fitness coinciding to work together, exactly how yet, is of course still in the air.
– I have also seen and written about how inexpensive gyms have boomed and why their model works.
I have written about the majority of these issues (excluding obesity) on my blog if you care to look further into it.
What do you think?