Yesterday we brought you news that Twitter had acquired mobile blogging platform Posterous for an undisclosed amount of money. The two companies announced the sale on their respective blogs yesterday. While no one from Twitter or Posterous is saying so, it seems likely that Posterous will be closed.

Now it looks like Posterous users might see the writing on the wall, too. It seems they’re leaving Posterous for WordPress in significant numbers. Since February of 2010 WordPress has offered new users a tool for importing their Posterous blogs to WordPress. It seems that since yesterday’s announcement that tool has seen a massive spike in use. In fact, use of WordPress’s Posterous importer has risen by over 250% since yesterday’s announcement, according to a post on the official WordPress blog.

Now, as previously noted, neither Twitter nor Posterous said anything in their announcements about Posterous being shut down. Each post, however, included a promise to offer tools to migrate or back up their Posterous content “in the coming weeks.” It looks like a sizable portions of Posterous’s users have decided to get a jump on things and move their stuff now.

Of course, WordPress isn’t the only option available, but it does appear to be the easiest. As Lifehacker points out, it is also possible to migrate your Posterous account to another blogging service like Blogger or Tumblr. Until Posterous/Twitter release their own export tools, however, the process for moving your stuff to Blogger or Tumblr is a bit more cumbersome.

Posterous users, will you be moving your content? If so, will you go to WordPress, or to another service? Do you think Twitter will shut down Posterous? Let us know in the comments.