This morning's Chasseurs d'Images (french magazine) has two pages of rumours. They usually have insider info from Nikon but not Canon. Here goes:
JULY 2007
Sony : new 12/13Mpix APS-C sensor to be first seen in high-performance version in Nikon D300 (Nikon supply the steppers used to make the chips)
Nikon : D300. Like the D200 but with the 12M/13pix sensor, autofocus from D2X (?), new image processor, up to 3200 ISO with option to 6400 ISO
Panasonic : new 4/3 system reflex of their own design
AUGUST 2007
Canon : 40D replaces 30D. 12/13 MPix sensor, perhaps with 5D autofocus but the rest is same as 30D (viewfinder, flash, screen..)
SEPTEMBER 2007
Sony : Alpha 200 with the new 12/13Mpix sensor
Nikon : First appearance of D3 at Rugby World Cup
OCTOBER 2007
Olympus : E-P1 reflex for experts
NOVEMBER 2007
Nikon : D3 available
2008
Canon : 3D, 500D
Leica : R10
Sony: Alpha Pro, new sensor format close to classic 24x36mm