In my brief exploration of Technorati, it seems to be a website of techie blogs. I browsed a long time to find any interesting blogs in the Top Favorites--alth0ugh I did explore The Unofficial Apple Weblog. This blog had so much information one could spend days exploring it. I like how the Top Favorites page has so many features like a snapshot of the webblog, its URL, recent posts, and of course all that blog's relevant tags.
Regarding the Learning 2.0 search, I definitely had to put the phrase in quotes to find related blogs/posts. There were 187 blogs--it seems like people had just give their blogs that phrase name. There were 25, 489 posts about Learning 2.0.
I found a great blog dictionary under Support/Site Guide.