What do you get for the ticket fee? Do they give away free things like Google I/O? Will you build lasting networks of app developers? I wouldn't blame anyone for going just for the experience but I probably can't afford it for that alone.
What you get now: 1. Session vids come out same day or very soon after. 2. No more Q&A. 3. Keynote is live streamed. 4. Same cheap jacket, just a different number (representing the year) on the back.
What you've always had, and will continue to get: 1. Access to the labs. Good if you have a problem that can't be answered in any other manner. 2. Networking with other devs over lunch and after-conference events.
If you don't need the labs, and aren't going to be all that social, save yourself $1600.
(EDIT: don't know who's downvoting you for asking a reasonable question. Have an upvote to offset it.)
So only go if you have substantial and important questions to ask to help you solve some problem – and, as always (and unavoidably) with any conference, for networking. The cost is there to further encourage you not to waste that opportunity.
1. All the information. This has historically been very important, but Apple's getting faster and faster at putting out videos these days, so if you just want the sessions, you can save a lot of money by watching them from home. 2. Direct access to Apple engineers in the labs. Depending on your needs, this can either be irrelevant, or it can be priceless. 3. Networking. A lot of people at WWDC don't even bother going to a session every time slot and instead wander the halls talking to people (plus all the time set aside for socializing, such as lunch, after hours, and the few minutes in the halls between sessions).
I sat down with an Apple engineer who did not have a firm grasp on the English language, and he pulled out his laptop and googled my question right in front of me. He clicked the first Stack Overflow post, saw it didn't have the answer I was looking for, and sent me on my way.
Words cannot describe the rage I had at that moment.
Googling or using Stack Overflow to answer someone's question is simply wrong. Even if it was a really basic introductory question.
One year I was working on a kernel driver and I got acquainted with several Apple kernel driver developers during labs at WWDC. After the conference I could email them directly when I had issues. That was extremely valuable compared to going through Apple's official technical support incidents.