My alma mater, like many colleges and charities, offers the option for larger donations of setting up a charitable remainder trust. Basically, in exchange for your committing the donation while you're still alive (rather than in your will), they pass along some of the investment returns on those funds.
In the simplest form of this, you're basically buying an annuity; they commit to returning 5% (or something similar) of your donation to you each year. Since they figure they can get 8% to 10% returns by investing it in their endowment fund, this works out in their favor even before the term ends and they get to keep it all.. Meanwhile you get to claim the tax write-off from the donation and get a guaranteed income stream (which you do have to pay taxes on, of course).
Not a bad deal for money you'd otherwise have parked in bonds for the long term or that you'd use to buy a more normal insurance-company annuity, assuming you do intend to donate eventually. Or so it seems.
(There are more complicated versions where you accept more of their risk in exchange for more of their return, but the above covers the basic idea)
My questions: Are there any hidden pitfalls in these trusts to watch out for, or are they really as much of a win/win as they appear? And how early, and to what degree, should I start considering making these part of my retirement investment plan, assuming that I plan to route at least 10% of my estate to charity anyway?