So what did I choose?
A Sony NEX-7. Brand new on the market, it's about half the size and weight of a DSLR, but with interchangeable lenses allowing for lots of flexibility. At 24 megapixels, 10 frames per second, full manual controls and a large sensor, I knew that it would do everything I was looking for. It can also shoot full HD video at 60 frames per second. It was more expensive than what I had originally planned for but will likely be the last camera I'll ever need to buy.
Sure, it's still larger than my Canon point and shoot, but compared to what else is on the market, I think it's a great compromise to get the quality and features that a DSLR would give me without being enormous. The fact that I can still fit it into my purse or a jacket pocket is a huge bonus. Now I just have to learn how to use it!