Today is the 2nd anniversary of my initial pledge. To date, neither Red Cross or Unicef have come on board.
In the meantime, Bitcoin has raised 300 folds, making the terms of my initial pledge borderline unsustainable.
On the occasion of this second anniversary, I have decided to review the terms of my pledge to match better my donation target in dollar terms, while keeping the initial spirit of the pledge.

The new terms of my pledge, effective immediately, and valid until 23 Nov. 2015 are now:
1 - 10k USD equivalent in BTC (regardless of the BTC/USD exchange rate) for Red Cross whenever they join.
2 - 10k USD equivalent In BTC (regardless of the BTC/USD exchange rate) for Unicef whenever they join.
3 - 100 USD equivalent In BTC / charity, up to 100 charities (max 10k USD in total).

@Phinnaeus Gage, I don't really have the time to follow carefully this thread, and I don't know most of the charities, so I'd like to ask you if you don't mind to manage pledge (3) on my behalf, and to notify me if you hear about Red Cross or Unicef joining Bitcoin so that I can execute pledge (1) or (2). If you are ok, I'll send you a first installment of 5k USD for pledge (3), please convert it back to USD and use it 100 USD at a time for next 50 charities (please confirm the BTC address) and let me know once it's used up so that I can send you the second installment. Alternately, I can also send directly 5k USD to your Bitstamp account via Ripple (see: Deposit > Ripple > USD).