The number of Mac OS developers who don't also need to know something about iOS is going to be very small very soon.
So let's not worry too much about them.
That may be true. I am not saying we shouldn't worry about them. But the overlapping developers are overshadowed by the vast number of the iOS developers.
My guess is that part of the problem is that many of the OS X developer simply couldn't get in due to the large number of iOS devs. This means that Apple would have to force an equal balance which may piss some off.
The size of Moscone and the number of iOS developers make it, I would think, very difficult for OS X devs to get in.
In addition, iOS devs may come to expect the same spotlight they are receiving this year. Which could become problematic for Apple as developers on either side get pissed off with the switch in focus every year.
For everyone ELSE they'll now be expected to pay for 2 trips. It's more than just the convention ticket cost. There's also airfare, hotels, and missed-work costs. Taking 2 weeks away from developing is a noticable dent in your yearly workload.
Oh I agree, it is far more than the convention. But many developers attend other conferences throughout the year. They may have to drop one of the others or they may just switch off if the cost is too great.
As far as the two weeks, I am sure their vacation time adds up to as much or more time off. And they aren't necessarily taking a break from developing.
Development doesn't stop when you leave your office. I often am developing in my head, and of course I am sure they bring notebooks.
In addition, they are there to add to their knowledge. In those sessions and labs they may be able to drastically improve their code or add new features. The conference is about
developing. I don't think they are losing work but in fact making significant improvements in their technique and abilities. This is an extension of their work; educating themselves.
Add all that up and you'll end up with a lot of people who probably SHOULD go to both who are just picking one instead.
This is true, but I am sure there are more difficult choices. It really depends on how much they benefit. If the conferences help them bring in more money then they will go, if it doesn't offer much of a benefit then they won't. Just as they do now.
I'd be worried that you'd see that group of people grow: People who should attend both but end up only going to one. That's bad for Apple and they should avoid creating such a group of people.
Maybe, but Apple can do things to make it easier. I am sure they realize the consequences of doing this and may work to make it more affordable.
They could run them one after the other. This would at least reduce travel costs.