Eventually ALL those on DLA will be contacted to fill in a PIP claim form. Here is some information from Citizen Advice Bureau which explains about this changeover;
There is no automatic transfer from DLA to PIP. If you’re already getting DLA and you were aged 16 to 64 on 8 April 2013, or you become 16 after that date, the DWP will eventually ask you to make a new claim for PIP even if you have an indefinite or lifetime award of DLA.
The DWP will inform you when you need to claim PIP. If you fail to claim it, your DLA award will end. If you make a claim for PIP, the DWP will continue to pay DLA until four weeks after they make a decision on whether you can get it. There should be no break in payment if you move on to PIP
You will be contacted when they would like you to complete the PIP forms and for some this will not be until the end of next year 2015. However ALL people on DLA will be contacted even if you have a indefinite award you will still be asked to complete PIP forms during the changeover. You cannot choose to stay on DLA.
If you would like information how to fill in PIP forms please email us using email@example.com and we would be happy to send them out to you