What this article fails to mention is that it's already possible to invest in bitcoins in an IRA today, and you don't have to be wealthy to do it. And you don't need SecondMarket, the Winklevoss ETF, or any third party holding your bitcoins for you.
For about $1500 and a modest amount of effort, anyone in the U.S. can set up a self-directed IRA, which invests in an IRA LLC which you manage, which invests directly in bitcoins.
If you do this in a Roth IRA, you don't have to pay taxes on the earnings!
More info on self-directed IRA LLCs at
https://bitcointalk.org/index.php?topic=396783.0
