The WHFSV news article suggested it should be available from July. (http://www.whathifi.com/News/Logitech-releases-Harmony-Adapter-for-PlayStation-3/)
I do hope that $60 doesn't equate to £60 as it so often does in Rip Off Britain!
There are a couple of US sellers on eBay offering them for about £60 including shipping from the US, but I think I will probably wait until Amazon or someone else is stocking it properly.