It's been awhile since I even thought about Salesforce.com system availability, so I went out to http://trust.salesforce.com/, SFDC's new system status site, to check out the last 30 days and was impressed (see screenshot below).

Some minor interruptions, but no major disruptions. The table layout of the report made it easy to cut and paste into Excel, which revealed some positive trends for the trailing 30 days (see charts below).

In short, the number of transactions continues to grow and the response times are getting quicker.

The up and down oscillation in the transaction chart is due to non-working Weekend hours (and I suppose some planned maintenance downtime).

It's curious that weekend utilization of SFDC is ~33% of workday utilization. This is rather high, but I suspect that a large portion of this is probably from automated batch jobs using the sForce API conducting backups and synchronization.