Recently there is a big change in OpenCV2.2 to OpenCV2.3.
The new version contains many interesting features including new feature detector, ORB.
One might wonder about performance of each feature detectors in terms of processing speed, accuracy etc.
Here you could find brief information about these:
About feature detectors:
http://computer-vision-talks.com/2011/01/comparison-of-the-opencvs-feature-detection-algorithms-2/
http://computer-vision-talks.com/2011/07/comparison-of-the-opencvs-feature-detection-algorithms-ii/
Feature descriptors:
http://computer-vision-talks.com/2011/08/feature-descriptor-comparison-report/