Thanks to Dorothea Salo for noting that blog designs may be subject to copyright and hence impedimential to the harvesting and preserving of blogs. In my initial scan of her comment I thought she was invoking copyright issues having to do with the content itself, but on reading more carefully, the issue she raises surprised me. I confess It never occurred to me that TypePad might lay such a claim... duh! How ironic if these templates themselves stood in the way of proper archiving.
Simon Spero's followup comment would, I should think, answer this problem, though I've never cared much for reformating of content. As things stand now, many blogs are syndicated into so-called Planet Blogs, aggregations of the feeds of various blogs on a given topic or area, and reformatted in just this way. This entry, for example, appears in the Planet Code4Lib aggregator. Irony once again rearing its winsome head, I learned this by accident through perusing my referrer stats some time ago. No one ever asked if I wanted my content aggregated in this way (I do, I do!), and it does make it more difficult to know who is reading (readers leave evidence in my stats only if they click on the entry in Planet Code4Lib and actually get to my site itself... probably not the most likely thing).
Putting aside this anomaly, the content copyright issue is important, as otherwise only blogs whose authors will have specifically requested archival service would be captured unencumbered. A huge part of the blogosphere will remain in an ambiguous state -- without explicit permission having been granted for preservation and redistribution.
If you look carefully at this image you will see a yoda-like visage in the left part of this picture of a recent attempt to ward off the Ohio midwinter blues. Or maybe Elmer Fudd. We ain't talking the blessed virgin here, but hey... a vision is a vision.