If you plan to do anything beyond basic photography (which is almost a given since you're looking at the D7000!), or some odd niche, my advice is to always stick to Canon or Nikon. Period. No Exceptions. Nikon and Canon have a much, much larger assortment of lenses and accessories, including from 3rd parties. As a self-described semi-pro photographer, I can guarantee you'll get pissed at the Sony at some point.
You're choice of shots sounds like mine. Sports, portrait, weddings, etc.
That Nikon D7000 is an absolutely incredible body. I convinced one of my oldest and closest friends to get one, having never even used a camera, and now I can't get him to put it down! He uses it from everything to videos of the baby, to some pretty nice shots of scenery. If I ever got another backup body in the crop form factor, this is what I'd get without hesitation. (I shoot with a Nikon D3s, and have a D200 as backup.)
Printing is a pet peeve of mine ... so I print my own. Got an Epson printer for about $500, and never looked back.
Beyond that, the biggest weakness of the Sony is higher noise. Both Canon and Nikon have been making strides in this area in the last few years. It's really a "soccer mom" type of consumer body.
Now, all that said, I realize the Sony is a full-frame body ... but at what cost? Yeah, it's cheaper than full-frames from Canon and Nikon, but there are tradeoffs is noise, accessories, lenses (and lens quality), etc. I'll admit it's tempting, but it's really not what I'm looking for. And it's probably not what you're looking for, as a semi professional.
Above all, remember to buy your cameras from legitimate dealers:
Let me know if you other questions, need more advice, etc ... for this, or anything else.
While I know video, I'm a photographer at the core!
Thanks.