I disagree, Bitcoin is more expensive because you have to dedicate some time to learning to deal with it, and then you need to exchange it back to your local currency at a cost, so doubly inconvenient. You also carry currency risk. I don’t see much hope in donations until there is an actual Bitcoin economy, if ever.
With Bitpay there is minimal learning. Any charity competent enough to setup CC donations (or hire someone to do it) could handle Bitpay as well. Hopefully someday a company (Bitpay) or newcommer integrates CC & Bitcoins to allow a single "checkout" function making it easier for charities and small biz.
Granted Bitpay isn't free but it does have three advantages over credit cards:
* Harder to shutdown (i.e. wikileaks & VISA)
* No per transaction fees ($0.30 on a $5.00 donation adds up. Get 100K donations and you are paying $30K off the top).
* No chargebacks (and assorted "fun" like hacker groups using stolen credit cards to rack up millions in chargeback fees for charity).