Unlike in the New World, where appellations are still being defined (for example segmentation crazy Napa Valley, who seems to be in constant turmoil, most recently over a new proposed Mayacama Mountain range AVA), the Old World wine producing countries usually look at their wine regulations as being set in stone. For the most part, you are allowed to only grow the same grapes that were approved for your great grandfather if you want your wine to bear the appellation label. This can make understanding what type of wine you will get from a particular region easier for the consumer, but it can also be a source of frustration for producers looking to experiment.
However, Spain, who is becoming one of the biggest exporters to the US and UK markets, is one of the more liberal in this regard, particularly in it's lesser known regions. I would be surprised to see any changes in the regulations that guide Rioja wine anytime soon, but now Penedes, the region where Cava is produced, has now been approved for icewine. What's more is producers are allowed to artificially freeze the grapes, which is not permitted anywhere else in Europe. Icewine is normally created when the grapes freeze on the vine, and this is the only method available in Germany, Austria, and Canada, the best known locations for this type of dessert wine.
Although the 3 countries mentioned above each have their own version of icewine's history, Spain will definitely add a new chapter. The new DO (Domination of Origin) is called Vino Dulce de Hielo or Vi Dolç del Fred, and will apply from 2009. A general rule is not to drink your icewine with a food that is sweeter than the wine, and goat cheese is one example of a classic pairing, for example Garrotxa if you wanted to stay local to the Spanish version. Salud!