For the record, when dpreview wrote about the 1Ds in 2002, they said:
"The EOS-1Ds features a full-frame 11 megapixel CMOS sensor. The sensor makes this camera the first Canon EF mount digital SLR without any field of view crop . . . Despite the increase in resolution compared to the EOS-D60, the EOS-1Ds sensor has a larger pixel pitch because of its larger effective imaging area,"
This is another way of saying that the 1Ds became a higher resolution camera (capable of shooting landscapes, etc, with its 11 MP) more out of the natural evolution up to full-frame digital sensor than because they intentionally made a "high megapixel model" with an integrated vertical grip.
The EOS-1Ds is Canon's newest professional SLR. Based on the EOS-1D body the EOS-1Ds raises resolution to 11 megapixels, uses a CMOS sensor (just like the EOS-D30 and D60) and is the first Canon digital SLR with a sensor which captures a full 35 mm frame.
www.dpreview.com