Mamut recently bought the distribution rights for MYOB products in the UK and Ireland.  
The current MYOB products will be supported until April 2010 for the Windows versions and April 2011 for the Mac products.  Support means telephone support is available from MYOB and upgrades including payroll upgrades are supplied by them.  

MYOB intend to terminate the datafile reconfirmation process on 31 December 2011.  This will prevent continued use of their products other than in 'read only' mode from the first occasion on which a user's datafile requests reconfirmation after that date.

Mac products

Mamut have recently announced that their replacement product for the MYOB Mac range is planned to be available in April 2010. This is great news for Mac users in the UK. Existing users and anyone buying before the release will be able to use their MYOB products until the end of 2011 (unless they want to upgrade earlier) and then upgrade to the new product (additional charges will apply).  More details here.

Windows products

MYOB Windows products are no longer available in the UK.

More details of the Mamut range can be found here 

Founded in 1994, Mamut is a leading European provider of complete, integrated software solutions and internet services for SMEs. Mamut offers solutions integrating CRM, sales force, logistics, accounting, e-commerce, domains, e-mail, web hosting and security. Based in Oslo Mamut has 440 employees and more than 400,000 customers in 16 countries.