Hi there, I am currently looking at the aforementioned upgrade / replacement for a couple of reasons... 1. Going on a trip, which includes a tour of base camp of Everest and I am finding information on which lens would be good for the Sony to be hard to come by. 2. The list of lenses available for the Canon's seems endless compared to the Sony. 3. More people are shooting the Canon's and information for a newbie is a lot easier to find. 4. Don't feel like switching all my lenses, batteries etc when I do get bigger into photography, rather just have one brand to start and build on it. There are some of my reasons, what do you guys think? I can sell the Sony for a few bucks so getting rid of it is no problem. Also, if you support this decision, is it better to upgrade to the 40D over the XSi, even though it is less pixels, but more expensive? Thanks for any replies!