Sorry to betray the CHDK community but I've switched to a Nikon DSLR
First impressions - I'm missing the 'live view' with detachable LCD, built-in image stabilisation and the somewhat reduced size of S2IS.
On the other hand the picture quality is astonishing, out of the 10MP you get at least 8MP usable at 100%. Focus is fast and precise, no more focus-hunting in low light. Still having problem with focus on plain surfaces and vertical lines, but for improved response you would need a whole different class (and price) of cameras.
The kit objective (18-55) is very very sharp and wide - considering a crop factor of 1.5x you get about 27mm wide view compared to ~29mm for Canon (crop factor 1.6x).
The viewfinder takes some time getting used to, it is quite small, though not so dark as some may suggest for the pentamirror design. I've held a D300 in my hands and its viewfinder isn't much better. I'd say it's a step up above 350d.
I'm looking forward to getting a 50mm f1.8 lens and try manual focusing on that, at least you get a focus confirmation dot in the viewfinder when doing manual focus.
The reason why I switched to DSLR was because I wanted wide angle for landscapes and shallow DOF for portraits. Improved sharpness and megapixels are a nice touch but I would've settled with a 6MP camera.
Battery life - 500 pics later (400 with flash) I still have above 50% capacity.
When choosing a DSLR remember that you are investing in a system so get the cheapest body you are content with and then invest the rest of your money in good lenses. Remember, for lenses you get what you pay for.
Now, the whole system cost me about 370 Euro (~500$) for a lightly used, like-new, warranty still running, body+18-55. As a bonus I also received 10GB high-speed SDcards, vertical grip, supplimentary battery of higher capacity, polarizing filter, UV filter, remote control, etc
