There have been reports lately of Apple holding a secret conference for iOS developers. Now, let me just state up front so there's no misunderstanding: Other than the normal news outlets, I haven't heard any information about such a conference - I'm certainly not invited if there is such a thing going on. This post is just conjecture on my part.
But I'm not sure why this is news. Apple constantly has strategically important developers (and other partners, like wireless carriers) out to Cupertino to work on future product announcements and to be informed about future products. It certainly shouldn't be news to anyone that the people who get up on stage with Steve at keynotes and presentations (plus everybody involved behind the scenes) knew ahead of time that they would be doing so.
If you follow a lot of iOS developers, you'll pick up subtle hints about when some of them are on campus or on their way there. It might just be a "Wheels down SFO" tweet, a comment about the food at Caffe Macs (the cafeteria at 1 Infinite Loop which is quite excellent), or a dinner with certain Apple employees, but the signs are there if you know what to look for.
Unsurprisingly, Apple is just as careful about keynotes as it is with everything else. As a result there are constant "summits" going on in the weeks before any public announcement. Since Apple now spreads their product announcements around the calendar year, that means it's an almost constant ebb and flow of strategic partners.
The process to be involved with a keynote presentation is long, stressful, and involves many trips to Cupertino. I can't say anything more specific about the process without betraying confidences (I've never been directly involved myself), but rest assured that despite Apple's famous secrecy, if you're at all involved with the developer community, then there are likely people outside Apple whom you've socialized with who knew a fair bit about certain products before they were released. Even people who aren't directly involved with a keynote presentation have to, at times, find out information about products early, and in some cases even get access to pre-release hardware (though usually with strong precautions talem to keep photos or other info from leaking).
If this is a surprise to you, chalk that up to the fact that the third party developers who are involved understand and respect Apple's desire for secrecy and want to continue being involved with the process. Apple is not known for being forgiving to those who leak information of that nature.
So, is there something even larger than normal going on next week, perhaps a replacement for the Tech Talk World Tours of past years? I don't know. It's absolutely possible. But, what seems more likely to me is that Business Insider simply got a whiff of information about an ongoing process and interpreted it incorrectly. Apple is never idle, and we're less than a month away from 4.2 being publicly released. It's altogether possible (I'd say likely) that there will be hardware or other software announcements that will coincide with release of 4.2.
Frankly, I'd find it far more surprising if there wasn't a flurry of third-party developers going in and out of Cupertino right now and for the next few weeks. Whether it's a formal summit of any size, I don't know, but I have my doubts. The more people involved with something like that, the harder it is to keep it secret and the more likely a leak is. Right now everything I can find online leads back to the original Business Insider story. Despite requests for anonymous information, no new information seems to have come out.
My bets are on business-as-usual pre-announcement activity, not some secret conference. If it is a secret conference, the participants are likely only the most strategically important partners: people who have been involved with pre-release products previously.