Specialization can increase productivity at the expense of creativity. Specialists are certainly valuable (would you rather have a surgeon or a family practitioner perform your operation?); but creativity also requires cross-boundary thinking.
The creative consultancy IDEO describes its best employees as "T-shaped." The horizontal line represents breadth of knowledge over many subject areas, and the vertical line represents depth of knowledge and experience in a specific field. Some of their superstars are F-shaped or E-shaped, with broad interests and depth in several fields.
When you live broadly, learning about and getting involved in a variety of activities, you tend to think broadly. You're also more likely to be tolerant of others that think and live broadly.
Bottom line: continue to build your areas of expertise AND devote yourself to the pursuit of interesting new experiences. You'll have more fun while becoming more effective.