Dear original poster,
I am a lawyer of England & Wales (albeit non-practising) so I'll just the preliminaries:
1. Mainly because the WordPress.com hosting servers are located in the USA, I'm afraid USA defamation laws will operate with regard to any formal takedown action that might be made.
2. If the physical location of content origination is somewhere in the UK, then English or Scottish jurisdiction may apply -- that is, if you could nail down that blogger's physical location in the first place. Then it's a straightforward matter of serving an injunction on that blogger.
3. Broadly speaking, the blogger IS within his/her right to publish a commenter's name in the comment section. And that's probably as far as any Common Law jurisdiction (USA, England & Wales) will allow. If Scottish jurisdiction applies, I would suspect the situation won't be too radically different. There ARE some precedent cases (mostly American) that provides for extenuating reasons against publishing a person's name -- but in general, those cases have already gone to court (a situation that doesn't necessarily apply to your situation right now.)
4. As far as what I could see in that post & its comments, there ISN'T much anyone could do since the blogger hasn't publicised anything other than a name -- that is, no links to somewhere else, no actual personal details (e.g. sex, address, IP address, etc). In other words, a name is just a name, and quite often quite many might have the same.
5. As soon as that blogger takes to publicising a person's IP address (yours or somebody else's), then you MIGHT have a PRIMA FACIE ("on first impression") case for taking legal action. Prima facie is a good description, because then you have to go through the rigmarole of nailing down that blogger's physical address in order to serve "process" (litigation papers).
6. In absence or inability to get physical address, you might have to go through the long way round and subpoena WordPress.com for that blogger's IP address. To make things worse, THEN you have to subpoena the blogger's ISP for his/her physical address. If you're lucky and know which buttons to press, so to speak, you might die of old age waiting for action to happen.
7. If you report the case to the police (initially your local constabulary), they'll just tell you the above points. Understandably so, because they can't act on defamation issues occurring over the Internet since this particular stage of events are civil in nature and not criminal (yet).
I hope this helps to give a general overview. It's okay, my invoice is NOT in the post.