CleverClogs has a thorough searching features post for the ideal Blog engine…well done it covers the gamut.
This is a must and sometimes a frustration when newsmastering, filtering every which way for granular content, quality content.
So you can browse a blog tag in Technorati, but you can’t search within the tag of a single blog, actually you can’t search within Technorati Tags full stop.
The best would be to search within an OPML.
I’d also like to browse my blog tags in Technorati by adding them, eg. which of my posts did I tag “OPML” and “RSS”, it seems I can’t add these like I can in a social bookmarks service.