Here's the press announcement about that Linspire is to Base Linspire/Freespire on Ubuntu and Canonical to Use the CNR Commercial Software E-Commerce Technology
Read it here
Linspire will transition from Debian to Ubuntu as the base for their Linspire and Freespire desktop operating systems. (http://www.linspire.com/OSblocks). This will mean that Linspire users will benefit from Ubuntu's fast moving development cycles and focus on usability. The Freespire community will start seeing early releases of Freespire 2.0 based on Ubuntu in the first quarter of 2007, with the final release expected in the 2nd quarter of 2007, following the official release of Ubuntu 7.04 in April.