It's always interesting to watch the camera race from the local Japanese perspective. BCN publishes weekly information about sales of cameras in Japan with interchangeable lenses and from time to time summarizes them. Here's the first half of 2010 graphed versus the full 2009 year in terms of unit sales:
Yep. Nikon and Canon have switched places again in Japan. Canon's loses come at the gains of Panasonic, Olympus, and Pentax. Sony also slid (this was before the NEX sales started).
More interesting in light of Nikon's upcoming product announcements is that the number one model in terms of sales share in Japan was the D90. Nikon's order of sales went D90 (13% of market), D5000 (10.6%), D3000 (7.9%), D300s (1.3%). That's sort of top outselling bottom. But look at the Canon numbers: T1i (11.5%), T2i (9.7%), 7D (3.5%). That's bottom outsells top. You can see why Nikon might think that the upcoming D3100 intro is a big thing: the bottom two Nikons sell 18.5% of the market at home versus Canon's bottom two getting 21.4%. If Nikon wants to pull more share away from Canon in Japan, they need a "hotter" low end camera.
Meanwhile, in the distant Group of Four, Panasonic has shown a marked uptick, with Olympus and Pentax having modest ones. Sony slid backwards. Here's that grouping in a little better detail:
No doubt all these numbers will change in the latter half of the year. Panasonic is rolling out more followups to their original m4/3 bodies, Sony already has the NEX twins boosting their short-term share, and there are plenty more new cameras to come with the Photokina trade show happening late next month.
Note that the Japanese sales numbers don't exactly line up with the global ones. While m4/3 grabbed nearly 17% of the Japanese market sales in the first half of the year, sales worldwide are far more sluggish as traditional DSLRs are still doing better in the US and Europe than they are in Japan.
One thing is clear, though: mirrorless may be performing well, but it hasn't really changed the dynamics of there being a Big Two and Lesser Four. We have two different battles going on here: a supremacy dual between Nikon and Canon, and a breakout battle amongst the rest of the players. So far, Panasonic is the apparent breakout champion in Japan. But they haven't yet replicated that globally.