The Employment and Support Allowance will replace Incapacity Benefits for new claimants after October 2008. There is apparently, no compulsion for existing claimants to switch, but they can if they want to. Would be interested in your comments.
If you want to read more about the changes, see:
dwp.gov.uk/welfarereform/c2.asp
publications.parliament.uk/pa/cm200506/cmselect/cmworpen/616/61607.htm