We are currently experiencing degraded performance in our NA6 instance.  I am curious if anyone else is having these issues.  The most invasive issues occurred (is still occurring) today 2/18/2011 surrounding our AsyncApexJobs.  We have gone from these jobs being run in a few seconds to more than 10 hours on some and an average of 2 hours on the rest.  There has been no code or configuration changes on our part.

I am working with L3 support right now and will report what they find, but would like to hear if any of the community has experienced something similar.