Well, I've been away for a few days - the reason:
A trade show where I got to be present for the Aussie launch of the D300,
including a hands-on, and also managed to get a hands on of the EOS40D.
WOW, these are exciting times to be a camera enthusiast - both cameras are
very nice, and are starting to bring some new functionality (or perfect
existing functionality) to the DSLR space.
First take...
40D:
got to see this one first - looks very good. Liveview works very well. In
live-view mode it's almost like using a rangefinder, the camera is very
quiet with just the slightest noise from the shutter. AF in liveview mode is
quite quick - it drops the mirror down, focuses, then lifts the mirror, so
it's not really suitable for fast-moving action, but it's one hell of a lot
quicker than the olympus system. The screen is gorgeous - you can actually
see the photo well enough to judge how good the shot is!! it's amazing the
difference that a 2.5" vs 3" screen makes. As for handling of it, it looks
larger than a 30D - hard to tell for sure without having a 30D side by side
with it. My impression was that it looked closer to 5D size. But it takes
the same grip as the 20/30D so maybe it is only an illusion that it is
larger. 6.5FPS sounds good - i was also impressed by how quickly the mirror
dropped, it was surprising when shooting at 6.5fps how little time the
viewfinder spent blacked out.
One minor bugbear of the 40D is that they have maintained the horrible dial
positions the 30D had. I found that with the size of my figures, changing
things like ISO, exposure comp, etc was particularly awkward, because with
one finger pushed on the button, I had very little space for another finger
to turn the top control dial - seemingly impossible to do with 2 fingers of
the same hand. This meant that changing these settings became a 2 handed
proposition. Also, any controls that require the rear dial were also a 2
handed proposition, because holding a button with one finger, and trying to
turn the button with my thumb, made me feel like I was about to drop the
camera. The K10/GX10 still wins for positioning of it's dials, to allow
controls to be changed while in a shooting position.
Overall conclusion though - I think it's the first time I've used a new
Canon camera and thought "I want one".

D300 - 2 PM eventually came when this one got unveiled. At first I thought
the unveiling was for the lens - thought the camera was a D200. Seeing the
rear though and it was immediately obvious there was a change, with the big
3" screen. Once again, a nice large high resolution screen was very nice. In
live-view mode though it did seem a little laggy compared to the Canon, and
we couldn't work out how to get it to autofocus in liveview. In burst mode,
it felt slower than the canon - could have just been an illusion because of
the different sound, or perhaps we didn't have it set to full speed. Perhaps
it's because I've used Canon's more, but it didn't feel as intuitive - and
even the bloke from Nikon seemed to struggle at finding how to change
settings etc. Take the 14-24/2.8 lens off it, and it also seemed quite
light - lighter than the 40D. Not sure what type of chassis sits under it,
but it was surprisingly light for such a large camera. It did sit well in my
hand though, and controls felt to mostly be in the right place. The
viewfinder was large and bright, but fills with a mass of red when you
half-press the shutter button. Not sure it really needs 51 AF points.
Compared to the D200, it is practically indentical physically, with just
slight rearrangement of the back panel controls, and slight repositioning of
the PC socket etc.
Overall conclusion - it left me feeling lukewarm. It's a good camera, with
some good features, but I'm not sure it's a significant upgrade on the D200,
and not sure its a Canon beater. Nikon haven't announced pricing. They did
say however that the D300 doesn't replace the D200, but sits above it in the
range. They also indicated that the D200 won't be having a price reposition.
This leads me to guess that the D300 will have an RRP somewhere in the range
of $3k-$3.5k. If I was in the market for this level of camera, and didn't
have a commitment to one format - at that sort of money I think i'd be
leaning to the 5D, or save some $$ and go with the D200.
I still think though that unless they bring it to market for basically the
same money as the D200, that it is overpriced compared to Canon's offerings.
If they do that though, they will have to drop the price of the D200 if it's
to stay on - could mean D200's become a great bargain over the coming
months.
The 14-24/2.8 lens they had on it was very nice though. If only the camera
was full-frame to take full advantage of the lens. Unfortunately they didn't
have a D3 available to look at.