The gender recognition bill will allow transsexuals who were born or live in the UK to be recognised as their true gender. Upon applying to a gender recognition panel for a gender recognition certificate, an individual with a UK birth certificate will be able to receive a new birth certificate that acknowledges eir true gender. Neither applying for the gender recognition certificate nor birth certificate is compulsory; it is up to the individual to choose what ey wants to apply for.
In order to qualify for a gender recognition certificate, an individual must be at least eighteen years old, have been diagnosed with gender dysphoria, have lived in the role of eir true gender for at least two years, be unmarried, and provide the gender recognition panel with evidence of the above and a fee for processing. Having operations such as sex reassignment surgery are not necessary to apply for the certificate, but you must provide a statutory declaration stating that you intend to continue living in the role of your true gender until death.
Once a person has a gender recognition certificate, ey will be able to marry someone of the opposite gender (currently transsexuals are not allowed to marry anyone), receive a new birth certificate (so it will be harder for companies who demand potential employees' birth certificates to discriminate against transsexuals, for example), and be treated the same as anyone else with eir gender as far as pensions, discrimination protection, inheritance tax, social security benefits and the like are concerned.
Although transsexuals will be able to marry someone of the opposite gender, failure to disclose the fact of being a transsexual to a spouse will entitle em to end the marriage without a divorce if ey ever finds out.
Ministers of the Church of England will still be able to refuse to perform a marriage ceremony where one of the participants is a transsexual, although due to the privacy provisions in the bill, it is possible that ministers will not always be able to tell when participants are transsexuals anyway.
Although not perfect, the gender recognition bill, if it becomes a law, will make the lives of transsexuals in the UK easier.
For more details, see the web site of Press for Change at http://www.pfc.org.uk/
Update: there is now an official government page available with information on how to apply for a new birth certificate at http://www.grp.gov.uk/.