Are you working on http://usegalaxy.org (Main)? Logged into your account? And are not over your data quota (check under "User -> Preferences)?
All of of this is a "yes", then it would be normal to have jobs that use more resources (in general the tools found under groups staring with an "NGS:") queue into a waiting state while they wait for their turn to execute (this weekend or ever). Other jobs such as Text Manipulation may start right away (if not dependent on an upstream job that is queued). Different job types are sent to different types of nodes on our cluster. That all said, the NGS queue has been very busy, as Martin notes.
If you are not using a registered account, then only one job at a time will be active. A job holding a place in the queue counts as an active job. And if you are on another server, how the processing is done can vary.
It is not clear if you tried to deleted/restart jobs from over the weekend or not, but this is best avoided and will extended wait times.
Best, Jen, Galaxy team