Executives looking for some prescriptive recommendations on business ideas for 2008 should look at Eight Business Technology Trends to Watch (registration required) from McKinsey Quarterly. These aren't '08 specific, each idea includes examples of how it has been put into practice by innovators, in some cases for several years. Actually the title doesn't do the the topic justice -- my recommendation: no watching, just doing.
The authors tackle co-creation with the first two topics, and even that might not give the topic it's due. Often times co-creation involves clearing a significant hurdle, "not invented here" syndrome. The authors point out the significant downside of loss of control of innovation and intellectual property, but developing that intellectual property costs time and money. Sometimes making use of another organization's expertise makes for a winning go to market strategy.
Another downside the authors noted, competing for the attention of the best and brightest contributors, isn't just a problem when working with partners. That can strike internal projects as well, particularly at large organizations. That problem also falls into the "two-way street" category, partners aren't the only ones that get distracted by other projects.