Tumblr’s export of my blog hasn’t finished processing and I started it yesterday.
The WordPress import hasn’t made any apparent progress, and I started that this morning.
WP recommends waiting 24 hours, then contacting support.
If you do, you are very likely to get an answer like this:
“Your import is not off track, it is still waiting in our queue system as we have been seeing a very large number of tumblr imports. Once the queue clears, you will be next.”
(It’s a clumsy dance even when all of tumblr isn’t evacuating at once, this diaspora has not sped things up)