WordPress.com makes it easy to switch from Tumblr to their platform
WordPress.com developers have posted about an easy way to migrate your blog from Tumblr to their platform.
The process is fairly automated and does not require using Tumblr to WXR conversion tools available on the web.
WordPress.com comes loaded with post formats functionality which is similar to post types on Tumblr.
In addition, there are multiple themes which are similar in design to Tumblr blogs if you want to retain a similar blog format.