We regularly visit Malta in December, and enjoy the walking and the winter sunshine.
Malta is fairly flat, with a maximum height of about 760 feet, so walking is easy and there is not a lot of climbing. It still manages lots of hills and cliffs, and some stunning scenery. The island has been occupied since prehistoric times. There are some fascinating historical monuments of a kind you will not see elsewhere.
Malta is pleasantly warm in December, though it can also have some rainy days. In 2006 and 2008, the fields were much greener than we have seen them before. We sometimes have a couple of days of rain, but manage good walks on most days. As a general rule, late November gives noticably warmer and dryer weather than mid December.
There is a local bus service, which covers the island, and a regular car ferry service to Gozo. We usually spend about 4 days in two weeks walking on Gozo. Buġibba is a good centre for buses around the island.
There is considerable opportunity for watersports. There was an international dinghy race of the 'optimist' class while we were there in 2006. Winds are generally light, but you can get stronger winds in winter. You could windsurf or kitesurf, but you would need your own kit, a hire car, and a considerable amount of patience. There are a few good beaches, but they can be sheltered from the wind by cliffs depending on the wind direction.
We usually stay in Buġibba, where the hotels offer extrememly good value at this time of year. Food is good. There are many local restaurants. We enjoyed locally grown vegetables and local wine.
The Air Malta flight deserves special mention for comfort and service.
Malta has a population less than that of Edinburgh. They have their own language, their own government, their own airline, their own ship building and repair facilities, and several daily English language newspapers. They have their own currency, but adopt the Euro on 1 January 2008.
The BBC world service is available at certain times of day from local VHF FM radio stations.
They have recently joined the European Union. This means changes in Malta, and indeed some adjustment of the European Union to meet the demands of new members. It means more money for environmental projects and road improvements. The old buses with their dreadful diesel exhausts are being replaced. New cars will be fitted with catalytic converters. They are required to exercise more control of their budget deficit and to stop subsidising their local industry and transport. Malta could become a paradise for bird watchers if the trapping and shooting of song birds is restricted, as EU rules require. They had their own currency, but move to the Euro on 1 January 2008. One unexpected consequence is an increase in bank robberies, requiring additional security measures.
If you intend to walk in Malta, do make sure you have a recent edition of the Sunflower book, "Landscapes of Malta". This book includes some excellent maps. You should also print out the latest updates, available on-line.