I've never really been a Canon fan mainly because my very first SLR way back in the olden times (late '70s/early '80s) was a Nikon and I've had lots since
My DH wants me to get the Canon so that we don't have to buy more lenses
I'm leaning toward the Nikon D3100.....PLEASE give me any and all opinions!!!
You can actually take excellent pictures with any brand's dSLR camera. So it really doesn't matter whether it's Canon, Nikon, Sony, Pentax, Olympus, etc. Any brand's dSLR camera will take much better pictures than a typical point-and-shoot camera.
I think your husband has a valid point. If your family already has a Canon dSLR and is already invested in a few Canon lenses, then it would be more cost-effective to buy a Canon dSLR for you. He's right in that you can both share lenses. One camera can act as a back-up for another, especially if one of them breaks down.
If you did buy a Nikon dSLR, you'd end up buying Nikon lenses, while your husband buys Canon lenses. What happens when you go to WDW? Do you bring both dSLR cameras and BOTH sets of lenses?
Or, what if you both get really good and photography, and you both want to start investing in really nice lenses. Let's say your child plays outdoor football at night, and you'd like to buy a 70-200mm f/2.8 lens. You'd have to buy 1 for Canon for $2499 and 1 for Nikon for $2449.
Or, if you both want to take low-light photos at WDW, especially on low-light rides, you'd both be buying a Sigma 30mm f/1.4 lens at $489 each.
Or, let's say you've saved up enough $$$$ to buy a nice lens. How do you decide whether to buy a Canon lens or a Nikon lens?
Of course, these are just extreme examples. If your husband isn't shooting with anything except the kit lens and if you don't plan on buying anything more than just the Nikon + kit lens (ie. no plans to do anything more with the camera), then *maybe* having both a Nikon & Canon dSLR in the same household *could* work. But if either of you get bitten by the photography bug, things can get pretty expensive, supporting 2 different camera systems.
The previous-poster is right, though. You have to hand-hold these cameras yourself to see which one "fits" you the best (ie. feels best in your hands, has intuitive buttons & menus, etc). Like I said earlier, ANY of these dSLR cameras will give you excellent pictures. Ultimately, the camera you buy has to be one that you're happy with and that "fits" you the best.