Press Release from South Florida

Comcast Corporation, the nation’s leading provider of entertainment, information and communications products and services, today announced the launch of new, lower priced calls to Cuba. For the first time, Comcast Digital Voice® customers can make calls that terminate to landline phones in Cuba for the reduced rate of $0.79 per minute.

“We know that for many of our Comcast Digital Voice customers, the high cost of communicating with relatives and friends in Cuba is a constant challenge,” said Comcast Regional Senior Vice President, Filemon Lopez. “This is a competitively priced per minute calling rate for calls to Cuba and it is now available to all of our Comcast Digital Voice customers.”

don’t know about calling rates to Cuba, but it was a bit of shock to discover that to call Canada from Cuba was 2 CUC/minute after they’d lowered the rate (was something like 2.50 CUC/min).  Calling Europe was 2.50 CUC/min if i recall.
Have to admit though, never had any trouble getting through, and always clear sound.  Phone cards bought from Etecsa worked on most phones in the Varadero and Havana areas (don’t know how well equipped for international calling other areas are)

I find it cheaper to use skype to landline, much cheaper all round.