Poof! You have $70 million

There's a fascinating discussion going on over at The Chronicle of Philanthropy's Blog Give and Take in response to an anonymous 31-year-old philanthropist's request for advice on where to donate $70 million. The original request was found on the New York Times' Freakonomic's blog where it received over 500 responses, some serious, some involving marriage proposals. One response in particular caught the eye of the Give and Take blogger though and has me thinking too. It came from Jack B. Siegel, a nonprofit lawyer and author of Charity Governance blog, who suggested that the philanthropist should, "cool his jets." Give and Take explains:

Mr. Siegel writes that the 31-year-old has his entire life to be a
philanthropist and that he shouldn’t be too hasty with his giving.

What do you think? If the need is there now should he wait? Is there a false assumption here that a young philanthropist is inherently a less mature philanthropist? Would it be better to wait for several years when that money, wisely invested, could grow to an even greater sum? It seems to be important to the donor to invest large sums of it all at once to make a bigger impact. What do you think about this approach versus smaller donations over time?