Open Transactions as the next layer over bitcoin blockchain will work great.
a) very fast .. under 1 ms
b) does not require transaction in blockchain (OT will use blockchain only for clearing ... 1 transaction daily/weekly/monthly/yearly? .. is enough)
EDIT: it will work even GOVERNMENT ban bitcoin, ... blockchain is your bank / (government can disable new transactions ) but he cannot change history. (already existing transactions)
That's currently the only known method of instant transactions with crypto currencies, and is how Ripple itself works, yet it remains centralized. It can be destroyed, it can become malicious, it is not 100% safe, and won't be largely adopted by bitcoin enthusiasts.
Ripple is excellent example how it will not to work
1. centralized
2. malicious
3. not
4. won't be
... :-)
I see now that it is not based on a centralized model or minority trust. I'll look into it further. Will it be adopted, you think?
In bitcoin community any bitcoin holder can choose how to spend his bitcoins.
EDIT: sell for $115 ($50, ... $1500) or rule the world