So, just as an intellectual exercise, if I were to set up a community of like-minded bloggers, how to best go about it?

I envisage something like

http://example.com/ – aggregation page for blogs, recent content from fora
http://example.com/forum
http://example.com/blogger1
http://example.com/blogger2

etc.

OR

http://forum.example.com
http://blogger1.example.com
http://blogger2.example.com

Will the multiple user thing that WordPress do that? Or would I need separate WP installs, or Drupal, or what?

Let’s assume I can get chunky hosting (a reseller account, in fact) for this. All thoughts gratefully received.

Other considerations: each blogger to take responsibility for own blog w.r.t. design and plugins, but some subtle branding to be applied across all to identify it as part of the community.