I have posted this on the Czech Republic forum but thought I would add it here as well.
Just for information for anyone visiting Prague over the next few months.
There has been some permanent changes to transport in Prague mainly due to the extension of the Metro Green line.In particular affecting buses to and from the airport.
Also at the moment there is a lot of tram works in various areas of the city that will go on till late October.
The Fennicular up/down Petrin Hill will be closed from early September till mid-march due to major works being done on it.
details of changes can be found here.
http://www.dpp.cz/en/