Yeah, whatever feels best.
I echo earlier sentiments--buy the camera that you feel comfortable using.
I've invested in the Nikon system for years and owned a Canon 60D for video. I set my partner up with the Canon T3i as well. Since my first DSLR in 2004, it's always been a Nikon/Canon debate.
It took me years to realize that it doesn't matter which tool is better. What matters is which tool will get the job I need done. I do essay work and portrait work. I use manual lenses so I was able to plop them onto my 60D. I could use either system (800's on slave mode work with the 60D's flash! It's not that either is better at photo-taking; you can't lose out. Our cameras are amazing!
If you buy a camera, you are investing in a system (lens, flashes, batteries). If you buy a camera with a kit to resell it later, then choose whatever you like.
I have spent a lot of time with the D7000 because I was looking for a backup camera with video capabilities. Image-wise, I find the low-light performance of the 7000 beats my 60D hands down. However, if you are doing long exposures, the differences will not be a big issue.
If you care about video (sports and narrative portriature), the D7000 doesn't have the flexibility of the 60D but the video quality is great. It should be noted I bought the 60D for its video performance (what's the best tool for a job), which I found the 7000 lacking in certain areas of manual control (can't dial down settings in D7000 without exiting or setting it on auto-exposure) and metering (histogram during live-recording).
Since you are shooting low-light and sports, you may appreciate the D7000's performance. I find both LCDs to be similar. You might like the articulating LCD for over-the-head shots. If you do sports, this would help with vantage points, should you have access to the team after a victory or loss. Also, the dual SD cards might be nice for a backups when out in the field or the ability to designate one card for video capture.