I like this. Here are my thoughts.

I like...
I love the way this this shrinks down to a very narrow layout.

I also love the two column layout.

I think that styistically it is definitley going in the right direction.

I like the way that everything (or at least almost everything) is left aligned.

Ideas for making it clearer...

It is still to busy with two many different visual clues things- there are too many different layout elements. I've talked a little about this in the page I started on Interface design guidelines in the section 'Design elements'.

In this example, to distinguish label from value, you could either change font size, weight, or colour, and that would be enough, but changing all three isn't necessary. It also means that these changes are less available to convey other bits of information, like the difference between section headers and actual data, etc. i.e. if you've used bold to distinguish a field header then you can't use it again for links / clickable parts of the interface.

In this example, to distinguish between different fields in a section, this example uses differences in color and also horizontal lines. This means you have to use an even thicker horizontal line to distinguish between the wider sections. If you didn't use the first horizontal line, you could keep the second one less obtrustive.

What distinguishes Position, Employer, Nickname, Source and tags from each other and from any other fields? I don't see the rational for formatting these differently and would suggest they are formatted in the same way as other fields. This makes it much easier for people to remove the parts they don't need from the template, thus saving even more space.

Once you have started the two column layout, there are a couple of lines that go all the way across the page that (falsely) give you the impression that the content on the left is related to the content on the right. i.e. work phone is related to email, skype is related to website, privacy is related to gender. These should be removed.

In general, there are too many horizontal lines and some of them are unecessary, for example, the one between the actions and the start of the data. You don't need to signify this change because it is obvious. In contrast, you do need to show the border between two different types of custom data.

I think that a custom data group should always span the entire contact width and be able to have two columns inside it, rather than being half the width of the page. This will help people navigate custom data and see where headings are.

Hope this is helpful :)