Great platform for microblogging, regular blogging, and connecting with a wealth of great contributers in the tumblr community. The UI is easy to use and completely functional. The interoperability with other popular websites is a good as it gets.
Cons
Plagued with "technical issues". Error messages on a regular basis, posts that get lost, and completely lacking support, aside from a canned email response. To much wasted time dealing with technical issues.
Summary
A great platform, if they can address the regular issues that make the site bothersome to use.
I consider Tumblr to be the best blogging platform I've used, but it hasn't been without a lot of technical issues to make my overall experience less than perfect.
[Potentially] Great platform for microblogging, regular blogging, and connecting with a wealth of great contributers in the tumblr community. The UI is easy to use and completely functional. The interoperability with other popular websites is a good as it gets. Connect with Facebook, Twitter and feed posts to both. Operate your Twitter account from within Tumblr. Feed another blog into your tumblr posts. All sorts of cool tricks can be done to maximize your blog's potential. Serious tools for the serious blogger.
[But] Spending all morning trying to post, and emailing contributers who respond that they don't see their posts is not a good way to maintain a professional blog. It wastes my time and my contributers time.
I hope it gets better, as I will come back and revise my opinions of the potentially great platform.<br /><br /><span class='notifyMsg'> Updated </span>on Dec 2, 2010<p/>Tumblr has made various infrastructure improvements since I posted this original review. I would now completely recommend Tumblr as the definitive blogging/micro-blogging platform. The community is also stellar. The users on Tumblr provide above average content and personality, resulting in more than just a blog platform.
Tumblr is definitely working on 5 stars. Great work, guys.