The answer is an unequivocal: Absolutely!
I have already illustrated how the Jeep Community is an extension of Jeep.com that engages its passionate community directly as well as promotes the large number of Jeep communities that exist on social web sites like Facebook, Yahoo, etc.
The Nike+ Community is similar in that it engages its passionate member community directly from its own website. It is different in that it does not overtly interlink with other Nike communities that exist on other social web sites. At least not nearly as much as the Jeep Community site does.
The picture below shows the entry point for runners to track their mileage. A cool feature is the Community mileage counter that is constantly counting up the collective mileage posted by the Nike+ community. Kind of reminiscent of the McDonald's "100 Million Served" counter. Neat touch.

The next picture shows the entry point for finding and sharing events that the Nike community would be interested in. Nike clearly wants to encourage their community to run together and interact.

Nike also provides an information-rich blog entitled "Inside Nike Running". They have experts writing on a range of topics. So for the community members who primarily like to read and listen, they have a great resource. Nike also provides a Forum for members who are more vocal and want to share their own thoughts.

While the site is a little over-polished for my tastes, it absolutely provides a branded way for Nike to engage its community around an area of PASSION.
I searched on Facebook to get a feel for how Nike is expanding its Nike+ community by engaging with Facebook members directly. While there are a variety of Nike+ groups created on Facebook (ex. the "Nike+ Challenges" group), none of them appear to have a lot of momentum which may be due to the fact that the Nike+ website already has a lot of engaging content.
I really like the "Nike+ Running Monitor" Facebook application and how it connects Facebook and Nike+ website members.
"The Nike+ Running Monitor is connected to the Nike+ website, giving you the ability to share your running information with the Facebook Network.You have the ability to add your profile summary, runs, goals, challenges and much more so you can show off how well you are doing and to keep you inspired!"
Nike clearly has a great strategy for engaging its passionate community with useful information and tools that enable them to feel part of the larger community. If you look at each of the screenshots above, you will also see how Nike makes it easy for community members to find their running products and learn more about them. It's a great noninvasive way to market/advertise to people who actually care about the products.
What's the bottom-line benefit to Nike? Customer loyalty, word of mouth referrals, increased brand equity, and increased sales. They also likely have a much higher ROI on their product-related advertising since they are engaging well qualified customers directly.
Further Reading:
Why Build Social Applications into a Website?
Why Develop a Facebook Application?
Social Media: Rent or Own?
Search Advertising vs. Social Applications
You can find even more recommended reading in the Social Business section of the Ringside Networks website.

