I can see it now... once Bill starts concentrating on his foundation you will find a push to make all contributions to charity go through the Gates Foundation. You will still be able to send money to other charities, but will be "encouraged" to do so through Gates' Charity Explorer, bundled for free with all Gates Foundation's packages.
Unfortunately, the Gates Foundation won't work very well with other charities and will not respect their protocols. The Gates Foundation will claim to be innovative, with projects like handing out computers to the poor, even though others have been doing so for many years previously.
Quarantine had better watch out too, because, through the Gates Foundation, many bugs will be introduced into previously pristine locations. You will also find that their projects will often compromise security.
But for all these problems the Foundation's work will look very attractive and it will be easy to do basic donations. It's upgrading to more complicated schemes (a yearly occurance) that will cost you.