The NYSE has wrapped up a dry run this weekend and is now aiming at a crucial phase-in of its hybrid electronic trading system. The system, to be launched this week, is in many ways the centerpiece of the NYSE's execution system--for the next few years anyway--and it is by no means a slam dunk. One floor broker told the AP that tests were certainly not a failure but highlighted some areas of improvement. Which is to be expected, to be sure. But it is clear that any real failures once the system goes live will be used by the floor denizens in their we-provide-value PR campaign. So while there is every reason to believe that the NYSE has thought all this out, there is still a reason for nervousness at the Big Board.

For more on the tests:
- Here's an AP article
- Floor traders losing ground in other exchanges. Article