This excerpt taken from the NDAQ 10-K filed Mar 15, 2006.
The merger of NYSE and Archipelago will create a strong competitor.
The recent merger of NYSE and Archipelago will create strong competition for us, particularly if NYSE is able to create its own electronic trading platform or migrate its trading business to Archipelagos platform. NYSE has stated that it intends to develop electronic trading capabilities that will compete directly with Nasdaqs. In addition, the merger with Archipelago has given NYSE access to ArcaExs electronic systems. If NYSEs trading volume increases to our detriment as a result of the merger with Archipelago, it would have a negative impact on our operating results.