I think a DSLR is the best way to go. Here's why:
1. One school of thought is that as a beginner, you should start with an entry level camera and upgrade to a better one when you get better. Another school of thought is to go straight to the "best" you can afford; that way, you don't lose on the entry-level unit when its time to upgrade (you are already there).
2. A prosumer cannot be upgraded. At some time, you will find that your prosumer has no value left. Sooner or later when you get better, you will want to move to a DSLR for the better picture quality etc etc.
3. While DSLR camera bodies also get obsolete, the lenses you can keep. At least your investment in lenses is protected.
4. If budget is a problem, may I suggest you look into purchasing a second hand Nikon or Canon DSLR - these 2 brands are the most common and you can easily find accessories and lenses for them; both new or second hand. These days a second hand Nikon D40 body is going for the price of a new point and shoot. If you can get a good f/2.8 lens to go with it; some people like the Tamron 17-50mm f2/8 or the Sigma 24-70mm f/2.8; you would have made a good start. Do note that 3rd party lenses like Sigma/Tamron/Tokina may not hold their value as well as the original brands, and performance wise, they usually don't fare as well, but they are usually much cheaper.
5. Besides Canon and Nikon, you might wish to check out the Sony DSLRs as well. The advantage of a Sony is that Image Stabilization is built into the camera body as opposed to being incorporated into the lenses (unlike Nikon and Canon). While Canon and Nikon argues that building VR or IS (what Nikon and Canon calls their image stabilization) into the lens let them tailor the IS to the different lens, having IS built into the camera bodies would save you a lot of money in lenses once you start owning a few lenses (and you will - SLR owners suffer from a disease known as "lens lust").
With regard to whether 17-50mm or 24-70mm, the 17mm is more useful for taking landscapes and large groups while the 70mm is better for taking portraits. Or you could go with the 17-50mm f/2.8 and a prime Tamron SP90/Tokina ATX100/Sigma 105. All these 3 lenses are f/2.8 and have 1:1 macro, so they serve as a macro lens as well as for portraits.
Don't forget you will also need accessories like a sturdy tripod (just bite the bullet and buy the most sturdy one you can afford so you don't have to upgrade later when you find your cheap, lightweight one not up to the task) and at least one flash unit that you can fire off-camera and has manual [flash] power controls. In this regard, I regret purchasing the Nikon SB400 as I find it too limiting. I cannot fire it off camera without purchasing an expensive PC (sorry can't remember what PC here stands for, but it is not personal computer; I can't get it to work with an inexpensive optical trigger) cord and I cannot control its flash power manually as I don't own the Nikon D40.
I personally own a Nikon SB800 as my primary on camera flash with a couple of Nissin Di466 (they have a built in optical trigger and I can control their output power manually).
Being a Nikon shooter, I read bloggers like Thom Hogan. The Strobist also give very good advise on flash usage regardless of brand of camera you use.
Hope this helps.