The Companies Act 2006 (the "Act") will be fully implemented by October 2008. However, many elements are due to be implemented earlier. Below is a link to the department of trade and industry website with details of the timetable for implementation of the Act. The following parts of the Act will be introduced from 1 October 2007:

Part 9 (exercise of members' rights)
Part 10 (a company's directors), other than provisions relating to directors' conflict of interest duties, director's residential addresses and under age and natural directors
Part 11 (derivative claims and proceedings by members)
Part 13 (resolutions and meetings), and, related to this, Sections 485-488 of Part 16 (audit)
Part 14 (control of political donations and expenditure)
Section 417 of Part 15 (contents of directors' report: business review)
Part 29 (fraudulent trading)
Part 30 (protection of members against unfair prejudice)
Part 32 (company investigations: amendments)

http://www.gnn.gov.uk/environment/fullDetail.asp?ReleaseID=267665&NewsAreaID=2&NavigatedFromDepartment=False