Google Street View for the Czech Republic went live earlier this month. Prague and some nearby cities such as Mělník and Poděbrady are included, in addition to the D1 freeway to Brno. However, it looks like Brno is not yet available. I have linked to the original Google announcement and show the coverage map and some selected street views. You can scroll around on the embedded street views or click for a larger version.
There were other updates to Google maps this month that affected the Czech Republic. There were changes to the look and feel of the maps that improved the readability of such items as street names and roads. The latest update added more businesses to the map with an icon to get detailed information. It looks like this data covers the country.
Google Street View announcement on the Google LatLong Blog
A gold medal-worthy Street View update
Google Street View Coverage Map of the Czech Republic (highlighted in blue)
Municiapl House (Obecní dům) in Prague
The Čertovka and Charles Bridge (Karlův most) in Prague
View of the road to Mělník and the Mělník Castle