Shortly after our post went live, 37signals founder Jason Fried left a comment, clarifying that they are toying with the design of the sign-up page, but that all of the old plans are still available.
"While we used to have four plans on the sign up chart, today we only have three," said Fried. "Same prices as before, just fewer plans displayed. A while back we used to have six plans to choose from, but we found that was ultimately confusing customers. So we went to five. Then we went to four. Now we're experimenting with three."
Fried echoed Hansson's earlier statement that the changes are purely experimental and that they may continue to alter the plans listed on their sign-up page, depending on their findings.
Interesting. Thanks for the update. So the news is that they are merely toying with the idea of making $49/mo the new "cheap" plan. That would eliminate the free plan (do they still have that?) as well as the $12 and $24 plans.
They don't have the free and $12 and $24 plans listed on the website anymore as far as I can tell, but perhaps you are able to downgrade to one of those plans after signing up for one of the other plans.