You've got any plans for your blog. But before you sign up for any hosts it would be insightful, savvy posts, there are practical considerations - like where to host it.
Who is Hosting This has put together a great little study into the blog hosts of the top 100 bloggers.
Check out what the top big brother's of blog host their site on. Sites like boing boing, lifehacker, readwriteweb, mashable, problogger, smashingmagazine, seth's blog and others.
On top of the list is Media Temple, Datagram, BlogSpot and Six Apart.
Yes you heard it, 8 of the top 100 blogs use Blogspot, (like me too, maybe some day you will find in the top blog spots) and 4 use Six Apart to host their blogs. It goes to show that while most would advise you set up your blog on your own hosting and with a platform like WordPress (which rocks the world) that you can actually grow a successful blog on a hosted platform like Blogspot.
Of course do keep in mind that many of the blogs in the top 100 are in networks so they just go with who everyone else is with in their network and some of the services that the bigger blogs use are probably out of the range of what most bloggers can afford.