In addition to providing a custom setting slot on the mode dial, a feature of which I've always been a big fan, the SX10 IS' mode dial rotates freely for 360 degrees rather than stopping at C and making you reverse direction to get to movie capture. This is nice, plus atypical.
Canon replaced and moved the multiplicity of buttons with the same simple dial and five-way navigation switch that it uses on its compact point-and-shoots. While I like the dial, it doesn't provide enough tactile feedback to match the control with the settings. For instance, when changing shutter speeds it doesn't feel like there's an equal amount of travel for each stop or indication when you've reached the next one.
I'm not thrilled about the placement of the review button; it's a bit too out of the way and I repeatedly forget where to find it, which isn't helped by the low contrast blue-on-silver labeling. However, I do like the dedicated movie capture button, which works regardless of whether you've selected Movie on the mode dial.