Good advice thus far. I'll add to it by saying that it's really important for you to try and get to a shop and look at the options which are available to you in the budget you've set. Physically holding the camera's, looking at their menu systems, and seeing what fits YOU best right then and there, is a great start.
Remember, the goal is to take that camera with you at all times (if possible), but if it's not comfortable to hold, or if your ability to get the shot you envision in your head is hindered by a lack of proper buttons, controls or a poor menu system that takes too long to get to a simple feature with, then that should be an automatic NO.
I'm personally not impressed by any of the new Nikon mirrorless systems. Some of the specs are impressive, but none of them matter much since the output I've seen looks not so great (IMO) I don't care about how fast the shutter can fire, or that the AF is deadly fast if the final output is soft, and the noise at ISO 800 is ugly.
The new sensors are smaller than those in 4/3rds systems, they're also proprietary which means another new size to deal with. That also means a lot less lenses, unless you purchase an adapter and use manual focus lenses. I just don't understand the market Nikon is going for with the new system, given its price point. But you'd have to do some real research to understand that in its self.
As RM said before, think about what you think you'll be shooting. If you have no idea, then honestly, a smaller profile DSLR might actually be the best way to go since it leaves you with the most options to learn from and grow with.
That said, if you do have an idea of what you think your style will be, it will be easier to help you from there. An important thing to note when going into photography, is that when you purchase an DSLR, you're not just purchasing an easily disposable thing. You're buying into a "system". The lenses you choose are even more important than the body, but you first have to understand why you want which body you're looking into.
For instance: Full frame, or cropped? Rely on auto focus all the time, or have more control with manual focus? Sony makes nice bodies, but the lenses are only kind of ok. But you can always slap some extremely nice manual focus lenses on an Sony body and get amazing results. But that also depends on what you'll be shooting.
Shooting sports? Need good focus tracking? I've always had great results with Nikon in terms of keepers, and Canon's higher end bodies just can't keep up in that area. You can look around the web and find many of the same complaints.
There's a lot of factors to consider. But if shopping for an DSLR, you should try and stick with the brand you initially choose because it can get costly when purchasing multiple lenses, lighting systems etc.. Do your homework and take your time!
I'd be happy to answer any further questions. Just lay em' out there.
On another note, I was looking at the Olympus 4/3rds system and the Sony mirrorless, and am very impressed with those as far as output quality goes. I'm leaning more towards the Oly system for a few reasons. Mostly because the lens options are more abundant. Secondly, the UI is more intuitive. I'm not liking the balance of Sony's kit lenses on their NEX bodies. Too bulky. But output looks great, even at very high ISO. Either system takes adapters which will fit all of my Nikon lenses, and that's important.
The Sony system is cheaper by a couple hundred, but I don't mind saving up for something I'll be happier with in the end run. Oh and yeah.. I'm kind of in the market for a new system as well. I'm planning on getting a mirrorless camera, and leaving the DSLR for studio work only. So I guess we can go through this together.
Here are some links for you to check out reviews and samples:
http://www.stevehuffphoto.com/ (I like this dude. Regular guy/photographer without bias. Just calls it as he sees it. doesn't get paid by anybody to do reviews) And he's good at what he does.
Tom Hogan:
Nikon Digital Camera and Photography Articles by Thom Hogan Good info in general. He's got some good links to follow as well.
www.nikon-cafe.com I'm a member here. Great people, very laid back and no ego's from what I've seen. Lot's of good advice that goes beyond Nikon products. A lot of the members have bought into mirrorless systems and post tons of samples and reviews.
Fred Miranda:
fredmiranda.com: Specialized in Canon - Nikon SLR Cameras, Forum, Photoshop Plugins, Actions, Reviews, Hosting and Digital Darkroom Another great forum full of pros. Great reviews, great images and great people.
Had more links in mind, just don't remember which! More later.
Doug
Edit: Almost forgot about the very respectable Canon Forums. Here's a good thread on one of the new Nikons:
http://photography-on-the.net/forum/showthread.php?t=1095402&page=3
