UK and presumably the rest of the world will have to wait until next year for iTunes in the Cloud.
Apple announced on Monday the iCloud at the WWDC 2011. Part of the iCloud is a cloud based iTunes. Apple will allow you to sync all your purchased music into the cloud and access from any other device. For the ripped mp3's Apple offers iTunes Match. iTunes Match finds the corresponding iTunes track and adds it to your iCloud collection. This is not free. Apple will charge $24.99. The iCloud will launch this fall globally, but the iTunes related iCloud services are likely on a very different schedule outside the US. For starters Apple has only announced iTunes Match pricing for the United States on Monday. The Telegraph as dug around a bit in the UK and apparently Apple just started negotiations with the loclal music rights organizations about the new service. Industry insider estimate that the negotiations will reach in 2012.
Apple will have to negotiate deals with local labels and music rights organizations in each country, putting the launch of iCloud iTunes on different schedules around the globe. For consumers the lack of a global media rights management organization is again a major pain in the neck.