Something I found that snuck under the radar:
http://news.bbc.co.uk/2/hi/uk_news/england/merseyside/8549613.stm
Turns out an atheist protestor got the same charge, but ended up with a suspended 6 month jail term, 100 hours of unpaid work and a £250 fine. Basically a much larger punishment (the preacher got the fine), but no one heard about it because the catholic community certainly didn't get up in arms about it.
The government is at least keeping their silly law consistent, I suppose...