Verizon, a company traditionally known for being ultra-controlling with its network and devices on its network, is opening its network in 2008. As Om puts it, "given Verizon’s track record of tight-control of its network including the user interface, this is a huge announcement: akin to Mikhail Gorbachev responding to President Ronald Reagen’s call to bring down the walls."
In practical terms, there aren't a lot of CDMA phones out there compared to GSM, so it's not (initially) that big of a deal. For example, you still won't be able to get an iPhone on Verizon anytime soon.
The really important line in the announcement, however, is that "any application the customer chooses will be allowed on these devices". It's about time. I wonder if Verizon will finally stop disabling the GPS and otherwise crippling their devices... If this is the case, I might actually be tempted to consider CDMA and a switch when my T-Mobile plan is up.