Resist the urge to add new features.
Live-chats, picture sharing, collaboration areas, member blogs, and video uploading all usually do more harm than good (and these are just the obvious examples).
Beyond a forum/discussion area, there are few features a community essentially need. Unless there is either a clear demand for a new feature or there is a sufficient social density to get the benefits (more on these in a second), it hurts the community to add them.
With too few members, new features dissipate activity. This causes long-term negative impacts. If 30% of members talk via live-chat instead of via a forum, all discussions receive fewer responses, the community looks empty and loses momentum. That momentum matters more than you might think.
Most new features are added on a whim and not based upon community need. It's usually better to refine your most used features than add new ones.
So when should you add a new feature?
If you have a highly active community, but the sense of community is relatively low, it makes sense to offer features that will encourage members to share experiences in more personable ways; like a chat room feature.
If members have a low level of familiarity with each other and limited levels of self-disclosure, offering a feature to upload images can make sense. It helps members build trust and familiriaty and spur a greater sense of community.
But adding new features is strategic. You measure which features have succeeded, and which haven't. It's not something to be done on a whim. You add specific features for specific reasons. Those are based upon community development.