If you want my honest opinion, if you want to make money off photography, upgrade. It’s an investment, I recently dropped 3000$ to upgrade some equipment. It’s addictive, you always want another lens, another flashgun, another umbrella of softbox… but it’s totally worth it. @sweetteaindahouse : I always have a point&shoot with me for traveling, or my Nikon D40 which is lightweight with my SB200 flash which I can still bounce and still delivers very crisp images. I use a Nikon D200 for shoots, wedding and events, which I adore. If you want to continue and have that possibility to expand, upgrade… Sony cameras are good, considering they bought Minolta. For their DSLR format cameras, I would wait a bit before getting a Sony.. I would rather trust Nikon, which has a very broad selection of lens and Canon. I find that Canon equipment is slightly more expensive than Nikon, but the Canon sensors are very efficient as well. My other suggestion, go in a camera store (not best-buy, a real photography store) and check the models. Check your budget, and TRY both brands. The “feel” the camera will give you is very important. If you don’t like the way it feels in your hands, you won’t enjoy shooting with it.
If you want to have good websites for reviews for DSLRs, try http://www.dpreview.com/ and my personal favorite, http://www.kenrockwell.com. Photography is all about learning, feeling and seeing. I saw photographers with 8000$ cameras that had poor image composition, poor lighting… It’s not the camera that makes the photographer.. so keep that in mind.
Cheers, and good luck!