There's a nice article by Matthew Alderman and a great discussion on "Further Thoughts on the Heraldry of the Ordinariates", a recent post on the blog The Anglo-Catholic. The post and ensuing discussion can be found on-line at: http://www.theanglocatholic.com/2011/02/further-thoughts-on-the-heraldry-of-the-ordinariates/
Quoted in the post, and also responding in the comments is Father Guy Sylvester, a fellow heraldry enthusiast, a blogger in his own right (disappointingly, I cannot currently locate his blog, Shouts in the Piazza; it appears to have been closed), and a really nice person to boot! (I had the opportunity to meet him in Quebec at the International Congress in 2008.)
And the comments really get into some interesting back-and-forth discussions, on such topics as this one initiated by Father Andrew Crosbie: "Why are citizens of a republic bothering with Heraldry?" I'm certainly not going to try to get into all of the different aspects of heraldry and the use of coats of arms generally, much less the special usages of ecclesiastical heraldry, that are discussed there. Please feel free to click on the link and check it all out for yourself. It's a fascinating discussion, even for those whose interest in the heraldry of the church is not all that great.