Where I work we've recently put together what we call the Development Standards Committee which is tasked with improving our procedures, processes, methodologies, tools, standards, and whatever we think would help us become a more effective team.
We've got a spreadsheet of items that we've ranked and are going to start tackling from the top down. We've got things such as better source control (currently on SourceSafe), implement a bug tracker (such as Mantis of FogBugz), peer code review, move to .Net 3.5, possibly move to some form of Agile, do more actual team development rather than single developer per project type stuff, and some other things...
What do you think are some key things that can make or break a development team? What should we add to this list?
Some additional information: We have about 12 people on our windows team, and about fifty in development if you include all platforms. We want to improve as much as possible for everyone, but we're our biggest focus is the Windows team. All of us have been here for a couple of years at least, so most of us know each other and work together pretty well.