One reason Ripple will likely fail in my opinion is this concept of allowing USD to be shifted "anonymously" among accounts. At least their marketing spin said you could do this. The recent laws about transfering USD around will mean this will likely be restricted or stopped.
You can transfer Bitstamp USD IOUs anonymously since Day One...
Though SnapSwap requires a US bank account...
Every Gateway does whatever it wants.
I did about 500 trades in May-June...
And you cannot get any Tax Compliant report on Ripple network trading activity...
So it's a Big Fat FIAT Laundering Machine.
*** OpenCoin claims it is not responsible for any of this activity. ***
FINCEN and SEC exists for the very purpose of shutting down dodgy things like Ripple...
CEO Chris Larsen has a history of tangling with US authorities like the SEC.