Like Steve Rubel, I also contemplated on moving my blog to Tumblr. For the same reasons: the social factor, the simplicity, the absence of hosting headaches.
Why didn’t I take the plunge? Because I don’t trust it (yet). Too many of my friends have complained about the downtimes. What disturbed me the most was when I logged in to Tumblr after almost 2 years, there was hardly any changes. There is still no robust capability to import a WordPress blog & its comments, and there is still no satisfying backup feature.
Apparently, I am not alone.
Tumblr reminds me of Remember the Milk, who did very well at its initial launch, offered impressive features … and stopped right there. They still refuse to adapt to the changing needs of its users, or open themselves up to the possibility that maybe, just maybe, their customers might be right.