Do I need a new camera?

It’s been about a year since I last went through this. The result of my last plea for help was a number of recommendations and I ended up buying the excellent Canon Powershot S90. It really is a great point and shoot and I think pretty much exactly what I needed at the time to help me learn a little more about photography. I always figured it would be good test to be able to play with and figure out whether I eventually needed to move onto something more. I guess the main thing that disappoints me a little about the S90 is its slow speed, it can only take about a shot a second in RAW. I often could do with something faster. Also while its low-light performance is better than anything I’ve ever used before it still isn’t as good as I’d like. I could certainly do with a longer optical zoom but that’d have to be combined with something that used faster shutter speeds I guess.

So I’m starting to get a little itch again, fueled by people talking about cameras across twitter all this morning and planning a honeymoon visiting an active volcano in Hawaii. So I’m starting to wonder if its time to look for something more, but I confess I don’t know whether a DSLR is really for me yet. I don’t know enough about lenses to really know what I’d be looking at right now and I’m pretty concerned that I’d just never actually carry a DSLR around enough to make it worthwhile. Micro 4:3 seems like a smaller yet still more powerful option but again I don’t really know what I’m looking at. What actually are the benefits of these over my point and shoot?

So I am asking my good friends of the internet to once again help me out. Should I look for something new or stick with what I have for now? Are there any good books that it might be worth reading to learn more about photography or is a learn-by-doing approach as I’ve been using for now the best way?