It's still the same product, just a redesign. Basecamp is great, and it set the standard for many in the industry, but I was much more excited about their future when they had a diverse product offering.
According to them it's not the same product (remember listening to a Mixergy interview where it was stressed that they were different - different code, solving the PM problem in a different way).
Edit: just found the product page for Basecamp Classic (http://basecamp.com/classic), man it looks pretty ugly!
haha yes, it is ugly. One of the reasons my team left it behind a few years back. Tried a bunch of pm systems and strangely enough, the two we loved most were free (Asana and Trello).