The HM Treasury "Budget 2014" document (link) indicates that the government intends to consult on the following further changes to the GPDO 1995 and the Use Classes Order 1987:

• GPDO 1995: Proposed new PD rights to allow "more commercial uses, such as warehouses, light industrial or certain sui generis buildings, to become homes" (i.e. amendments to Part 3, to allow changes of use from B1(c), B8, certain sui generis, etc to C3).
• GPDO 1995: Proposed new PD rights to help "businesses seeking to expand, including allowing changes to car parks, loading bays and non-retail facilities within existing boundaries, where there is little impact on the environment and local communities" (i.e. amendments to Parts 41, 42, etc, depending on whether the above term "businesses" is referring to A1, A2, B1, etc).
• Use Classes Order 1987: Proposed creation of "a much wider ‘retail’ use class, excluding betting shops and payday loan shops" (i.e. amendments to Use Class A1, etc).

It's not clear whether the above proposed new PD rights are in addition to, or instead of, the proposed new PD rights for A1 properties that were announced within the HM Treasury "Autumn Statement 2013" document in December 2013 (for further info, please view this post).

For reference, the parts of the "Budget 2014" document that relate to the planning system are as follows:

"2.249 Commercial permitted development and retail – In order to support businesses, the government’s review of the General Permitted Development Order will include consultation on creating a much wider ‘retail’ use class, excluding betting shops and payday loan shops. The government will also consult on introducing greater flexibilities for businesses seeking to expand, including allowing changes to car parks, loading bays and non-retail facilities within existing boundaries, where there is little impact on the environment and local communities.

2.250 Change of use (planning) – The government has made changes to the General Permitted Development Order to allow more flexibility between use classes. The government will consult on further changes to allow more commercial uses, such as warehouses, light industrial or certain sui generis buildings, to become homes.

2.251 Judicial Review reform – The government, working closely with the judiciary, will launch a new Planning Court on 6 April 2014 to fast-track disputes, including big construction projects.

2.252 Nationally Significant Infrastructure Planning Regime Review – The government is committed to making the planning system work for major infrastructure projects and will shortly publish the outcomes of its consultation on the Nationally Significant Infrastructure Planning Regime, including a series of measures to streamline and improve the process."