I'm right there with you, but with one of my Erasmus offers, I actually asked for some extra time to get back to them so I can hear back from my first choice - a different Erasmus program. They said yes, so I figured that in the event the commission bumps me to the wait list for choice #1, I've got a plan B and I would be thrilled if someone eventually declined for a similar reason. We're all in a state of anxious email refreshing, but some folks get to relax sooner than others I guess. I am NOT in the relaxing group right now....
I accepted other offers to UK universities weeks ago, but they let me know it would be okay to accept so I could meet the deadline and withdraw if I needed to.
Hope this helps!