ergophobe - 6:43 pm on Apr 25, 2011 (gmt 0)
Drupal/Joomla have good "normal" CMS features but the integration of blogs doesn't seem that great
How so? I'm not familiar with Joomla, but I can integrate blogs pretty fully with Drupal (using the *Views* module - always key for mincing and serving data).
I would assume, though I don't know, that Joomla can do much the same.
A good search system that can group results as Articles, Featured Blogs, User Blogs, etc.
This is where I would think you'd run into bigger issues. Most CMS have fairly rudimentary search and it seems like the way people are going these days on high-traffic enterprise systems is to use an Apache Solr-based (Lucene, Sphinz) search, especially faceted search. This invokes a fairly substantial bump up in infrastructure (typically runs on its own server AFAIK).
Another hurdle is that Solr is Java-based, but you seem to have that expertise already.
If you have an hour devoted to just the question of search for just one CMS, this is more or less state of the art for Drupal: