I have jumped on the Tumblr bandwagon, but I'm still using my blogger account. From now on, http://wnathanlee.com will take you to http://wnathanlee.tumblr.com
The reason I'm using two separate blog accounts (and a Twitter account)?? I'll try to break it down for you, and I'll look nerdy in the process:
Blogger: will be used for text-only blogs, updates will be sent to tumblr and facebook.
Twitter: synched with facebook status.
Tumblr: photo updates; also used to import all blogger posts and digg articles. Twitter feeds are displayed, but not part of the RSS feed.
Facebook: importing twitter feed as status, importing blogger posts as notes.
The purpose of the separate blogs is to offer different levels of "reading commitment" to you guys. Tumblr is there for people who want it all, and facebook synching is available for the less interested readers.
Also, my band Maida Vale has been heavy on the tumblr updates lately. If you want some more reading material, go to http://maidavalemusic.com