http://crackberry.com/dropboxs-new-arbitration-clause-takes-away-your-right-sue-so-take-it-back
I use DB a lot since it seems to be the most integrated cloud storage solution across my many platforms and apps. I don't think this will affect me since I don't keep anything on DB important enough to sue over, but your milage may vary.
The article did prompt me to resurrect my long dormant Ubuntu One account just in case.
"arbitration is a faster and more efficient way to resolve legal disputes, and it provides a good alternative to things like state or federal courts, where the process could take months or even years."
That is true.
I have it in all my contracts.
The problem with arbitration is that the end result is often fair and reasonable. Some people hate that.