Photokina starts on September 21st. This is the every-two-years show that's the biggest of all the various photography trade shows. You might not see the top execs out in the booths, but they're in private rooms and hotels briefing their best customers and subsidiary managers on all the latest and greatest and even upcoming products.
Here's the usual scenario: from mid-August until the show starts we have a fairly constant stream of announcements from the major players. Basically, they're trying to make announcements that'll establish their basic booth announcements and position them vis-a-vis their competitors. Once the show starts, we usually don't get any additional product announcements, per se, but we often get the "behind glass" quasi-announcements. In other words, when you get to the booth you discover some future camera and/or lenses sitting behind glass where you can't touch them or try them. The ultimate tease. (In those private rooms, though, the special guests are usually getting a closer look.) After the show closes, everyone is in how-fast-can-we-get-it-shipped mode. So: Announce, Show, Ship, in that order.
Nikon has announcements scheduled for the week of August 16th (I believe there are two days of announcements: the 17th and the 18th, but I'm never invited so I don't know for sure, I'm getting those dates second hand). As Nikon Rumors has reported, we're going to get the fall Coolpix line (including a new P camera), a low-end DSLR (the D3000 replacement), and some lenses. Conspicuously missing from that list are the D90 replacement, the D700 replacement, and the mirrorless camera. I sort of doubt Nikon would make another announcement prior to Photokina (historically, Nikon doesn't do big announcements that close together--it overtaxes their subsidiaries, amongst other things).
So, we either have Nikon about to do something they usually don't do (lots of announcements close together), or we're going to get the D90 and D700 replacements after Photokina. The mirrorless camera? Well, it either is the Coolpix P about to be announced, or we'll see it under glass at Photokina for a much later release (e.g. first quarter 2011). I can't give odds on any of these possibilities. With the recent turnover in high management, it's possible that we'll have some changes in announcement timing and style, too. Or maybe the new execs will just keep the old pattern intact. There's no track record to predict from at the moment.
As I usually take September off from doing this near-daily Web thing, Photokina always gives me fits. Fortunately, it's only every other year ;~). Suffice it to say that I'll cover Nikon's August announcements, but then probably go silent for a long period (I won't be in reliable Internet access, anyway). But come October, expect a lot of commentary. Who knows, I might even have had some hands on with something by then, too.