Firstly, an apology to all those who have been receiving my bogus RSS feeds over the last week or so.
Essentially, due to complexity in my feed pipes: from WordPress through Yahoo Pipes to Feedburner caused the echoes of posts. I had recently updated the Feedburner plugin in WordPress and oddities in my Feedburner configuration left a textual hall-of-mirros.
Thanks to @duncanriley, @Tuna and a special call out to @suewaters for bring this to my attention.